I'm kinda in the same boat as you. I have been hunting for a trailer for about 4 months now, doing ebay searches, free classifieds, newspapers, other websites etc etc.
here are the conclusions that I have come to.
Length needed is equal to the length of the tractor/fel/attachment. In my case a 16 footer would fit snugly, but for 2 foot more of cost the increase is worth every penny. Additionally, it isn't just about how long the equipment is, it is about balancing the load so as not to put too much tongue weight on. and to be honest I don't want things hanging over the trailer, and I would like to have a little room for a box or two to store some stuff in.
Most manufactureres I have researched are building very similar trailers, and like kinds of trailers are all priced the same. The difference in pricing is pretty much about the c channel thickness, the deck, lighting, type of axles, tires etc. A same sized trailer that is selling for 800 less is selling for that much less for a reason. Not always, but most of the time it is an inferior product being used or the type of paint.
I have narrowed my search down between a bri mar and a moritz. Mainly because they seem to be closer to me, and time and distance is money. an 18 ft 10k trailer is running about 3800-3500 across most companies in PA. I can get it cheaper in other states, but then I have to pay their temp tag fees and haul it home. Gas isn't cheap and time is money. There are some that sell for about 2900, but the paint is junk, or the wires aren't sealed, or no stake pockets, or something that just doesn't quite add up. There is an old timer who welds up trailers for part of his living, and he makes a decent trailer, but he buys his parts where everyone else does, so the cost is about the same. I'd throw my business his way, but if he closes shop tomorrow i would be out of luck.
I too have chased too many used trailers through all the aforementioned areas, and every one needed decks replaced, new tires, or had bad wiring. Too many times the guys said "yeah, there are breaks on there, but I never hooked them up and didn't use them". I'm going new, and will likely have my new trailer in the next week. With my luck, there will be a pristine used trailer for sale 2 miles down the road for half the price, after I buy a new one.
Don't know if this has helped you or not, but I consider it trailer therapy after all the research I have been doing. it almost becomes mind numbing. One last tip, there is a guy on ebay who sells brand new bri mars from time to time with no reserve. But he hasn't had an equipment one in a long time. His 16 ft dual piston bri mar dumps were selling for about 3500-4800, and the 12 and 14' ones were selling pretty cheap. Cheapest guy on ebay that I have seen for a quality trailer near me. WV I think.
