I have a 5x8 utility trailer. Gotten good use out of it. Also have a 6.5 x 16. Out grew it a couple years ago when I bought a new tractor. Can get tractor on trailer, but not with an implement. Tractor tires scrub the wheel wells. Probably need a 24', then a bigger truck to pull it. Never ends.
That size it’s hard to compete with tractor supply. Find one with a little surface rust or scratch on it, they’ll discount it. I’ve did it a couple times.
I can tell you this. I bought one from Tractor Supply a few years ago. It's junk. First thing, axle came out from under it. Expanded metal weld has broken all over. I had to add support to the tongue. Wheel bearings went out in both wheels in less than two years. Only use this trailer for local trips to the hunting woods and back. Next purchase will be better quality, and one that the tail gate will be removable.