His last confirmed payday was at UFC 200 and was 70k + 35k. That would be from his current contract. I assume that that deal has elevators, and thus he may have made as much as 100k + 50k for his last fight (just a guess). Considering where he's ranked and the fact that he's a fairly big name in an important division, you'd think he'd want a decent raise. Bellator would probably give him 250k flat, plus he'd be allowed sponsors.
Also, I wouldn't be surprised if Rizin gave him a solid offer too, considering he was popular in Dream. But hey, Sage Northcutt has more Twitter followers, and that's probably what WME will base their contract offer on.