There's one for women 21 to 33 who are willing to donate their eggs for Invetro. That pays $8,000!!
I don't think it's worth it for only $8,000. I have a friend who has done it twice the first time I think she got $30,000 and the second time around $50,000. You have to take fertility drugs for several months which aren't exactly easy on the body or mind. Then the procedure to retrieve the eggs isn't very fun.