Question for guys who change boats every year or two

I'm in the market for a new boat. I purchased my current boat new and it is going on 10 years old. I've often thought about changing boats every other year but I worry I'm going to take a massive depreciation hit. For the guys who do this, do you have a great relationship with your dealer and because you buy frequently you get a low price? Do you trade your boat or sell it private party? Based on past experience, I've never been offered a fair price on a trade so I just keep my boats a long time but I'd love to buy a new boat every other year.