shinya aoki.. gilbert melendez definitely... id like to see ben askren in the ufc dont think hes anywhere near GSP but definitely worth a shot.. hector is a beast and definitely in the top 5. id also like to see jacare in there as well .. technically nate marquardt is probably the best outside the ufc but obviously he aint heading back anytime soon
I doubt it costs that much, seriously doubt he is getting that kind of money with Bellator.
Then you also need to factor in that if they want to the UFC can offer him percentage of PPV, which Bellator cannot. Sponsorship deals for UFC fighters are probably far healthier than other orgs, free health insurance, bigger profile etc etc.
There are dozens of reasons outside of base pay why a fighter is better off with the UFC than any other org.
Your forgeting tim the beast silva ;-)