I have NO IDEA what he can make in Europe, or even which leagues pay best. I don't know what kind of evaluator Oats is either. BUT...
Oats says Petty would benefit tremendously from coming back for another year, in his system, and that he believes if Petty continues to improve he could make the first round next year.
I have to wonder if this is similar to the situation in football with Ronnie Harrison. Harrison ended up starting a good bit of the year for the Jags, but they got him for 3rd round money. If he had stayed another year, the money, AND the guarantee, would have been a HUGE difference. Similarly, if Petty comes back, and plays well, and gets drafted later first round, I am sure the money for his family would be a tremendous difference.
One also has to ask how many that move forward early, and go the foreign league route, end up making good money in the NBA.
And finally, China virus has put such a wrench in things that it's hard to know what to think.
I also wish him the best in either regard, but I selfishly hope he comes back for another year, his degree, and a chance to raise his stock significantly.