I have no target of profit anytime I participate on this kind of contest but I have a limit on how much is the max amount I should spend. I will stop playing once I feel that my luck is over, no matter I'm in positive or negative. Just like the latest Deposit Race, I stopped when I made $150 profit as I felt that my luck was over when my balance seems to be stuck (hard to get more winnings/get more dead spins).
I am glad I saw your post today which shows that you know when to stop. Congratulations on your insane profits. If I may ask you to create a video of your journey of reaching an unspecified target (profits) from a $25 deposit, will you make and upload it to YouTube? We will be happy to share it and gain you huge number of unique views.
Maybe you can try the normal spins (not the buy feature)
I have tried normal spins and the results are not too difficult to get the Bonus round
Buy feature is really bad if you consider my experience. I tried it with demo at first and was amused. Then, when I bought it with real money while playing for real, I lost 75% of its purchase price.