I got a kit that was not complicated to assemble but it took a fair bit of time so I would say the price for this machine is pretty fair.

No idea about how well that one works, but I guess it comes with guarantee?

Better make sure to have a list of projects first, because while cool to have, you can just order 3d prints, you don't need the machine yourself. Or you can visit hack spaces and ask for a turn on their machine. And it's like... an actual waste of living space if you're not using it. It's actually in the way. Same thing as useless kitchen devices that sit on the counter and collect dust.

Then again, if you want to be nice and give your sister a nice gift, go for it.

Also idk how relevant money is to you, 800€ can buy a nice dinner, nice clothes and a weekend trip to a nearby city. Or like... think about an actually high quality bag or purse that gets used daily. Definitely the price range to discuss it with her and not just show up at her door with a huge box. 😅