I'm most likely going to build myself a trailer to replace a well worn flatbed car hauler from 1986 soon. That trailer, (much like "Krusty") is well worn in and out. Probably model from my skid steer trailer which is constructed from 2X6-3/16" wall tube frame, and 2X6X1/4" wall tube comprising the tongue with "Torflex" Dexter axles. Xmembers are "jr" I beam with this one and it's been good but structurally deficient from rust these days. It was new with my 1845C in 1995, or 1996 and has been given no special care. Hydraulic surge brakes on this trailer that I really don't care for. They are not bad when loaded, but trailer is so heavy it "pushes" the pulling truck when empty under moderate braking and slick conditions.
As you mention it will cost more to build one, but will track straight behind the pulling unit and won't abnormally wear tires as quality can be controlled easily when building for yourself.