The UFC apparently offered
quite a bit more money to Brock Lesner than the WWE.
Probably makes sense for him to take the WWE offer though at his age and deteriorating skills. Its still a lot of money, except he doesn't have to train nearly as much to fake wrestle.
Basically about a month or two of work per year to just stay in shape and fake wrestle vs at least 6-7 months worth of work training for the UFC to get punched in the face, concussed, and probably knocked out.