Honestly. Its much more time consuming to change one item professionally.

Then to make 1000s in a factory setting.

15 is less then 1/2 hour when 6ou take all th3 other costs of running a small business into account.

As another said. A 20quid shirt 8s perfect for learning to play yourself.

Don't do cloths myself. (Little interest.) I make cushions and bedding etc for my little boat.

But you can hand sew such things. Will take a good while. Or find a friend with a machine who is willing to let you learn. You never know you may find a new hobby.

If you live near South oxon. Pm me I may be willing to let you play with mine when I get back home.

Once you learn the basics of using a machine. Plenty of good books d youtube vids on clothing techniques. Plus other stuff. Their are 2 great subs on reddit. Hopefully they will federated soon. I should ask the mods if anyone is interested. I may be willing to run sewingforbeginers here.