Hello,
I've gotta back up John's reply, I just finished building a trailer so that I could get the 1000 lbs worth of welder and tools out of my truck bed, and trust me, a 16' trailer for <$1000 is pretty good if you aren't wanting something special and can do the job with wood. Mine was a 5' by 10' bed, tandem 2000 lb axles, and it probably cost well over $1500 in materials(it was built to withstand a nuclear holocaust, however). Axles were about $400-$500, steel around $700, and though I used some wheels and tires we had laying around our barn, $60 per wheel and about the same for tires, not to mention wiring and brake kits.
Hope that helps,
G. L.