Actually I have a better suggestion than the one I originally posted. I should have thought of this first since I have actually done this before.
Used trailers are very expensive. Often more than you paid for the boat. But a crappy boat sitting on a decent trailer still sells for the price of the boat, not the trailer. Look around you will see I'm correct. You can find a decent trailer with a crappy boat sitting on it all over Craig's List and eBay. I purchased a rotten C-Hawk fishing boat for $500. It was sitting on a dual axle trailer that I wanted for a Rhodes 22 sailboat. I then stripped off the anchor chocks, engine mount, compass and cleats and sold the stripped hull for $100. So I got a duel axle trailer, and all of that hardware for $400. You will never be able to find a used trailer for $400. Try looking for a nasty boat sitting on a decent trailer.