I tried with my Stattrak pp-bizon, i got up to like 3000 credits ($3) when it gave me 1380 credits for it, cashed out the pp-bizon and got it back but then lost all the credits that i had left
I'm not too upset because I didn't lose the skin, I was a bit more smart this time and cashed my skin out and tried to play with the rest of the credits.
I find that once you get about 2x what you put into it, it seems it gets a bit harder to win.
Might try again later If I'm feeling up to it, lol.