I hear ya, I bought used!
Again, sounds like mostly dealer issues. They are deffinately boning you on the trade in and probably did on the purchase too.
Marine Max is a big outfit and I would think their corporate offices would try to address this. Have you contacted them? They send me a fancy magazine and do a lot of promotion stuff so you'd think they would be concerned about their dealers. Hit their website and see if there is anothe MM dealer near you and contact them. If they can't help then I'd write a letter to the president of MM.