Jake Paul's leaving a ton of money on the table in his upcoming boxing match ... telling TMZ Sports he's more focused on being a world champion than selling Pay-per-views.
The 26-year-old Problem Child is facing off against 35-year-old pro boxer Andre August in Orlando next month ... which is a stark contrast from his usual big-name opponents like Tommy Fury, Nate Diaz and Anderson Silva.
Paul says that's by design ... as he needs to take on real-deal boxers to both silence his haters and move toward his goal of being the best fighter on the planet -- even if it doesn't line his pockets like his other high-profile bouts.