Buyer's price is one thing, seller's price is another. Compare both campers for the sell price, and then both campers for the "buy" price. You did not provided the model number, so it's hard to determine apples to apples here. But you can do this yourself and see what the gap is, if you are getting a good deal or not. If you were to purchase both camper right now form the same dealer, what would the price of both be? If you were to sell both campers to the same dealer right now, what would they give you? Then only you can decide if it's a good swap or not.