Yup, another tire question? - same old... same old..

Our new TT came with 15" Marathons. Arctic Fox builds this nice trailer and then throws the cheapest tires on the planet on it!!! :R We have not used the TT yet and only have a few short trips planned the rest of this year. This winter it's going to the welding shop for an axle flip and frame mounted rear hitch. Then to the tire shop for 16" wheels with Toyo LTs. The tire shop will not give me anything for trade in on the Marathons as they will not re-sell them. Their reputation is that bad!!