Threw it together from scraps, I even rescued the wheels from a dumpster.
My only costs were the welding consumables and the 8mm rod end. I fished the trolley out of my local creek, it had been in there for a while and the bottom half was pretty rotten but the basket cleaned up nicely. The steel is 1" square tube offcuts also rescued from a dumpster.
She tows very nicely, extremely stable at all my riding speeds even with 60 - 70 pounds of groceries onboard.
I'm now working on another trailer to tow the kids and picnic supplies, a bit like a Burley but bigger and sturdier.