I Paid $15 for this one:
and am turning into a cargo/dog trailer, got no kids...
Here it is on the first test run at 103 pounds GVWR,, total trailer weight
that's a 70 pound floor jack in a 17 pound box n strap on the 16 pound chassis.
Still need to center things and work out details, finished it should be at $50.
My dog is only 31 pounds, finished total running weight should be under 65 ish...