Perhaps you can save some money and just make a new plastic bearing ?
My sack trolley had metal bearings which rusted away is salt water
So I knocked the bearings out..and used different diameter plastic pipes to build up a new non rusting bearing. I couldnít get an exact size pipe (plumbing waste pipes) ..so just cut a slot in the outer pipe and made it the correct size to fit. They donít run fast so wont melt. I little grease between the two plastic pipes keeps things running easily. Split pin and another (grey plastic) washer holds all in place. Solved my problem anyhoo.