I did like 10 15 paid studies when I was a student . I got paid anywhere between 250$ to 3500$. average around 700. most of them I stayed in the clinic from Friday night to Sunday evening. took a dose of a different drug and they took blood samples. it was great I just brought my homework. the 3500 one I was in the clinic for 2 weeks though. that one was a little rough but still better than working a random construction job for months to save up that much money. they had decent wifi and the food was okay