Hmm...well when I traded to Metropolis, I think I got $60 for a Voyager, 2 deluxes and a Scout. Which I immediately used to buy a loose Henkei Onslaught and something else. Not too bad a trade. Obviously they can't give you full market value because they still need to make a profit, but they tend to be more generous when it's store credit because you're keeping the business with them. They are called 'Toy Traders' after all.
And I can't seem to get rid of most of my unwanted TFs anyway... Maybe I could elsewhere but it's too much trouble shipping them out of the country.