MM, remember, two spares for the trailer, new electric brakes, wheel bearings and wiring. New trailer tires (use old ones for spares...... you will need them). All electrical to be soldered and heat shrink added.
Sandblast,followed by powdercoating (or at least Rhino Lining, etc on frame, check all welds, u-bolt's, spring leaf's, and light sockets.
There you go, your cheap trailer is ready to go, and don't ask me how I know all this stuff after fourteen round trip's to Wendover and back........................
Next comes support equipment, generator, compressor, canopies, tarp's, kitchen sink, etc.
A new 2nd mortage is in order at this point ( and I ain't lying, it's how I got here........)
your pal in arm's, Bob