Plenty of other people have already said it, but I see no problem with anything that two people voluntarily agree to if both parties honored their end of the deal and nobody was misled.
It's like if you bought a cue, got exactly what you were expecting to get get and agreed to get, for the price you agreed to pay, and then complained saying "I can't believe he charged me a thousand bucks for this cue, that's too much, I feel so wronged, blah blah blah". If you were forced to buy the cue and it was not a voluntary transaction on your part, then you just might have a legitimate gripe. If you were misled about the cue and got something other than what you agreed to, then you certainly have a gripe. But when you got exactly what you expected and what you voluntarily contracted for then there is no gripe.
If Mike makes his no refund policy known to you, and nobody forced you to have to sign up for his tournament, I just don't see how anyone can have a gripe with not getting the refund that they specifically agreed that they would not get. You don't have a right to be upset with someone for honoring their deal with you. It's just silly. You have a right to be upset when they don't honor their deal, but not when they do honor their deal.