Personal opinion - I wouldn't have thought that it's an IR violation to offer gold for someone not to attend a tournament. They've still got the choice of whether they want to pocket some gold or to attend the tournament. You're not forcing them to take either choice.
That being said, I'd personally advise just leaving the tournament subject alone. Let people enjoy them (or not) without complicating matters. As is normally said, if you're trying to work a way around an IR you're probably going against the spirit of the IR.
