Pez is right. If you only make it to one audio event this year, RMAF is the one to go to. It has the most manufacturers, the most friendly faces, and a nice laid-back atmosphere. Not to mention the Denver Tech Center area is fairly easy to navigate if you drive. As far as expenses go, you can save a few bucks by staying at one of the many hotels in a ~2 mile radius, but the convenience of staying at either the Marriot itself or the Hilton Garden Inn across the street is hard to put a value on. Just make sure you book early enough to get the show discounts at one of those hotels or before the others fill up. (or the prices jump up) Other than that it's just food. You can spend as little or as much as you want on that.
My only other advice is to go with a list of manufacturers and a game plan. You can NOT just see every room or you'll never hear anything you like for more than 2 minutes. If you don't know what you want to see already, I'd breeze (and I mean breeze) through with a notepad in hand on day one, then go back to really listen to the rooms that were interesting over the next two.
