This might be a good deal, a 5 x 8 Pace for $1,000. in Rochester Hills, MI:
http://detroit.craigslist.org/for/862595326.html
Saw Shores Trailer (Eastpointe, MI) list some prices on the Detroit Craigslist. I don't know if they are a good trailer, but FWIW:
Brand new enclosed trailers.
Pricing:
5x8...starting at $1495
6x10 side door starting at $1795
Other sizes and models available, call for prices. 586 777 7733
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The side door on the trailer pictured is nice. I noticed that Haulmark makes some low-profile trailers that will fit through a standard garage door opening height, which could be useful.