There is no formula, the price you pay is situational to the dealer on any particular day.
The dealer is trying to feed his family and he will want to profit on both the new sale and the sale of your old rig.
Use the K*I*S*S* method.
Sell yours and buy the rig you are looking at on a clean deal
Higher priced rigs of a certain type have a larger % of markup so the dealer can dicker more. The conventional thinking around here is that on a Motor home you should get about 30% off on a clean trade.
If you are looking for a higher number on your trade than is reasonable then the difference between what it is worth to the dealer versus your expectations for trade on your rig has to come out of the 30%.
The easiest way to avoid problems is to not trade but sell it yourself. The value of your rig to the dealer depends on how fast he thinks he can move your old rig and for what price. An example would be trading in a POP UP in November in the Northern U.S. The dealer will figure he has to hold it all winter or wholesale off to another dealer. Time value of money comes into play making the trade worth less to the dealer at this time.
How will you figure that into the equation?
