Or rather, PCs to Steve: "Go collect from the Mayor".
Mayor: "But I don't owe Steve money!?"
PCs: "Our bill for saving the town time and time again just came due."
Mayor: "Whaaaaa?!"
PCs: "If we were charging fair market prices for our work, this whole problem would never have come up. We were being nice, under the assumption that you fools would play along. You didn't. So now we are charging a retainer. 10% of your tax base and dealing with issues like this before they come to our attention sounds fair to me."
Almost-smart Mayor: "And if I don't pay up, you leave, leaving us defensless. Yup. Steve, come along, we'll arrange something for you." (and, probably, punish Steve for threatening the town's relations with the PCs)
Smart mayors would have dealt with Steve long since.
Mayor: "But I don't owe Steve money!?"
PCs: "Our bill for saving the town time and time again just came due."
Mayor: "Whaaaaa?!"
PCs: "If we were charging fair market prices for our work, this whole problem would never have come up. We were being nice, under the assumption that you fools would play along. You didn't. So now we are charging a retainer. 10% of your tax base and dealing with issues like this before they come to our attention sounds fair to me."
Almost-smart Mayor: "And if I don't pay up, you leave, leaving us defensless. Yup. Steve, come along, we'll arrange something for you." (and, probably, punish Steve for threatening the town's relations with the PCs)
Smart mayors would have dealt with Steve long since.