I would make the coach look nice, polish the rims (a big eye catcher) and put some treatment on the tires. Nothing shiny, just make them look clean.
Since your year Monaco uses the smaller 22.5 tires (255/70), the Hankooks are a great fit and ride exceptionally well. They're a reasonable replacement and you've already done your homework on what they cost. I would keep that number in your pocket and if the potential buyer presses you for new tires, use about 75% of what the new Hankooks will cost as reduction in sales price. If they go at you harder, use 100% and then hold the line.