Yep. Definitely got designed by someone living in an apartment sick of going down to the gym after work and paying for it and hated the idea of paying for a doorframe bar. Just the pull-ups alone have wide, normal, or hammer grip.

The design is just a few welds, pads, and brains. I.e. maximising with smart minimalist design.

Edit: The push-up handles are for form, but are also for bands to assist endurance pulls. It's so well thought out for like $100 USD. Built for 300kg and doesn't budge on dynamic movements. Also easy to breakdown for moving house.

Clearly, I'm a big fan. Granted, I'm a rock climber only, but we do more pull ups than anyone.

I want to respect your ability to make descisions for yourself. But my advice:

1. Open your mind to doing exercises that achieve the same goals with different equipment. Eg, you can increase effective pull up weight by switching to assisted one arms, then one arms, rather than stacking on increasingly huge numbers of plates. There is no such thing as the magical, perfect exercise - they all work about as well, unless you are competing in Mr Olympia. Pick the one that is most convenient for you and the equipment you have.
   1.1) I would also say - I don't want to doubt your commitment nor your current fitness level. But I notice you said you plan to do insane shit on this pull up bar. A far faster and cheaper solution could be a $10 used doorframe pull up bar that you use until you outgrow it. A solution doesnt have to be perfect forever for it to be perfect right now.
2. Scope out the municipal gyms near you, and look into financial aid programs. A gym with a simple barbell or dumbbell set, plus a pull up bar, is really all you need. Or if it is full of machines, that is great, too. Don't let the perfect be the enemy of the good.
   2.1) I will note that while I can imagine you putting togther a free standing pull up bar for next to no money using salvaged materials, I think you will find that achieving sufficient stability, durability, and load bearing capacity will be a bit of a feat of engineering. If you are trying to do, like, weighted kipping pull ups or muscle ups or something, the dynamic, non-vertical forces could quickly make your joints unstable via the large torsional forces you would be putting on the base. Making a truly resiliant free standing pull up bar is going to be much easier for someone who buys their materials new, uses good tools (like miter saws and hole saws, which are expensive), and who has a decent amount of carpentry experience under their belt - and doing it this way, even if you manage to borrow the most expensive tools, you can still expect materials to cost a couple hundred bucks with the price of lumber these days. A municipal gym membership, otoh, is probably like $15/mo.
   2.2) Same with buying dumbbells. Expect iron to cost between $1-2/lb. While building a functional home gym is a noble goal, a cheap commercial gym is often a better value.
   2.3) One more point on the gym and then I'll shut up, which is that I, personally, like gyms because they help me stay consistent with my training by putting it somewhere other than my home - so if I can motivate to go to the gym, I will get my workout in. Versus at home, I tend to be far more likely to procrastinate, since the option is always available. Plus, good gyms often have a social aspect that can be enjoyable.
3. You should find a different place to live asap. These kinds of landlords are, like, literal slumlords. Their whole ploy is to rent to someone they think has no other options so they will never complain or move out, then nickle and dime them as much as they possibly can. I would start reading up on landlord-tenant law, start documenting issues that you see, and get in contact with a lawyer (many will do free consultations to give you advice on your situation). If you have proof of issues of habitation, you can pay a lawyer, like, $50 to write a letter on their letterhead to your landlords saying you'll sue them if they don't let you break your lease and give you your full deposit back.
   3.1) Seriously, you're getting scammed. I know you are grateful to have any roof over your head, but that is exactly how people like this will exploit you. If you put the legwork in, you can find a place that is as cheap or nearly as cheap without shitbag landlords - and a landlord that charges more up front but doesnt nickle and dime you will probably leave you ahead financially.
   3.2) If you won't do it for your pocketbook or quality of life, do it for your gainz. Inhaling mold spores results in systemic inflammation, which decreases sleep quality and recovery.

Ah you might be able to use this stuff to build a freestanding thing in that case

I will start the analysis with the simplest case and then work upward. Supposing 75 kg on a normal doorway leverage-based pull-up bar and doing just purely-vertical pull-ups and curl-ups, this is within the design specifications for such pull-up bars. An example: https://www.garagegymreviews.com/equipment/iron-gym-total-upper-body-workout-bar

However, because this type relies on your downward bodyweight to press the bar into the doorframe, no swinging motion of any kind is allowed: all movements must be purely vertical.

There is another type of doorway pull-up bar that is akin to a tension rod, but I simply cannot ever recommend these in any scenario, because they have all the limits of the leverage-based one, in addition to also applying a weird expanding force that no doorway is ever designed for.

If the leverage-based pull-up bar was screwed in above the doorway, this would make it more securely attached, but not to the degree that you could swing full bodyweight around. And if you were already going to drill holes, you'd want something that definitely attached to the studs, so that it would genuinely allow you to swing full bodyweight away from the wall. Example: https://repfitness.com/products/wall-mount-multi-grip-pull-up-bar?variant=41067582914718

But maybe you actually want to swing in bitj directions from the bar, or may even over. In that case, you'd have to be farther from a wall or door and would looking at something that is mounted to the ceiling studs (properly called joists). Example: https://ultimatebodypress.com/products/ceiling-mounted-pull-up-bar-with-patented-reversible-risers-for-16-and-24-inch-joists

Ok, but wait, basically all of these remaining viable options involve holes in the wall, so none might be workable. Can we use a standalone/freestanding like this? https://thesportsroyals.com/

The issue here is that such a tower has no problem with vertical curls and pulls. But because the legs are fairly narrow, there's only a limited range of swinging forwards/backwards before the tower itself tips over, taking you with it to the floor.

Supposing your requirements are rigid, the only other solution I can envision is some sort of triangular frame like a children's swing set, where the center is a bar, where the triangles are as deep as they are tall. If the base cannot be that wide, then it would have to be weighted at its corners.

As a design, this is extreme difficult to find pre-made. But a variant would be to look at 4-post power racks, which can satisfy the depth and height requirements. For example, the REP PR-5000 can be configured as a 6-post rack, with the middle posts set using 30" depth to the front posts and 30" depth to the rear posts. In your case, would not mount the pull-up bars on the cross members as normal, but would put them on the middle post, at whatever height you want.

I don't have exact numbers right now, but such a six post setup would already weigh something like 140 kg in steel, minimum. And bring over 2 meter deep and 1.2 m wide, the geometry is highly resistant to toppling, even if you swung 200 kg inward and outward. If it needs any more stability, a power rack easily accommodates adding weight plates at each post, to really make sure it doesn't move.

But at this point, such movements would require 4 meter ceilings to do safely. And I think I may be entertaining the engineering here too much. What I will say is that if you're doing gymnastics, then you have to use gymnastics gear, not resistance training gear. Swinging is not a general design goal for resistance training gear. This is the same reason why an exercise pole (aka stripper pole) is not going to be comparable to steel conduit for electric wiring.

If there is even a spectre of a doubt that your gear isn't well-suited to your specific goals, then some reevaluate should be done. You may want to look at what a commercial gym has, if the same would work for you; gyms sometimes don't have studs or joists to use, so their equipment is selected accordingly.