One can often fund used kid's trailers for quite cheap.

The Aosom trailers look nice. A couple of comments though.

I much prefer the trailers with a frame that extends all the way around the wheels. It provides more protection for the wheels, but also is a much stronger design, especially with heavier loads.

I find the spring hinge to be exceptionally annoying, especially when pulling heavy loads uphill (and standing) when they create a surging motion. However, I will admit that the spring may have made it less traumatic when I wrecked my trailer.

I was pushing about 17 MPH along the side of the street, empty (ex kids's) trailer, at dusk. A right turn lane took off, and there was a low curb that I didn't see dividing the turn lane (for some unknown reason). Anyway, the right tire hit the curb, and flipped the trailer upside-down. A non swivelling connection could have thrown me hard. As it was, everything just seemed funky when I found the trailer upside-down behind me. But, no real damage to anything.