They can't/wont use hand veins for this, since they have to extract, process, and return the volume not used. IME they wanted an arm vein and only went after the inner elbow for the needle site. The hand vein likely isn't large enough to use for this purpose.
You could make $400 a month for 30 minutes a week. It was better than a part-time job, but definitely still a testament to the fact that we're all being robbed of our labor, seeing as how you shouldn't need it if you're a working adult.
Boy Boy made a great video about this. A lot of the blood is actually going towards silicon valley tech billionaires who think other peoples blood can cure aging. Companys also sell the blood at a profit so it's not like they're actually better than the red cross who give the blood to actual hospitals. There is a reason we don't allow people to sell their organs. Giving too much plasma can be dangerous. It shouldn't be any different.
In germany there is a limit how often you can donate. I think that is something that every country should implement. If you can only donate 5 times a year there is no real medical problem with doing it.
Interesting fact though: plasma donation is an effective way of dramatically lowering PFAS and other "forever chemicals" as well as possibly microplastics in the bloodstream.