In my experience, cash doesn't factor in. I've had some older players pass on options with large contracts, and there was no way there were gonna get close to what they passed up on the FA market.
I don't know if team success factors in, but I use options alot and, in my experience, they tend to stay more than they opt out. Its not a huge difference though. From what I've had happen to me, I'd say 55%-60% stay and 40%-45% opt out. I'd be curious about others' experiences though.