I'm impressed by a dealer that doesn't play the add-on-fees game. At one point in my search, I had asked a large dealership that we had purchased our MH from a long time ago, for a price on a new TT. Because I was a returning customer - he cut the almost $4,000 in added fees, in half.
I bought a nice 2yr old trailer from a small dealer (I'm going to give them a shout-out because they were so nice to deal with: Curtis Trailer in Schoolcraft, MI) about 30 miles away - there were no add-on fees, they charged for tax/license/title. The price was competitive, the trailer spotless. The salesman knew his product, and there was no pressure to purchase :-)
Always compare the out-the-door price! And it's fine to walk away if the price is more than you wish to pay - if you realize later that your expectations were a bit too much, you can always go back with a higher offer.