If Mika has no injuries and ends a professional career at age 35, he will have had a 13 year professional career. If he makes an average of 250k/yr over that career, he will have made 3,250,000 in his career. If he postpones going pro for 2 years and has an 11 year professional career, he will have made 2,750,000 in his career. That's a difference of 500k.

The only reason he should stay is if he believes staying for a year or two more gets him drafted. It won't. The mission killed his opportunity to be drafted. His only hope to get into the NBA is to impress in G League and get an opportunity.