I think Jacks comment is dead on, I was told 40 - 60% of wholesale on a good day for a trade-in of plastic by a Dealer acquaintance.

Karl - I think Lazy Days was blowing smoke at you, but I suppose you could get 80% on a trade while you pay almost full retail for the upgrade. If your that far upside down, just keep driving the Monaco and count the money you save. You also could try to sell the Monaco and your loss wouldn't be as great as a trade-in deal. Then you can shop for a Prevost with no baggage.