I don't know where you are (someplace in CA), that's the curse of leaving that off your avatar/screen name area, no one knows to be able to make a local reference.
In hopes this generic info helps:
Do you live in an area where they have weekly trash collections? Start driving through neighborhoods on the night before that area's bulk pickup, and sooner or later you're sure to find a cast-off you can use, take parts-from, or whatever. Just pick the whole thing up, don't try to field-strip it of what's useful to you and leave the bones in a heap where it was found.
I have probably five or six wheelbarrows I've rescued from such circumstances, needing various pieces. None has resulted in expensive outlays, all have been less than the same new piece. Fortunately, wheelbarrows are not getting Generation I, then Gen. II, then Gen III ABS, traction control, smog systems, or accident/pedestrian avoidance hardware/software, so you often can do some swapping to make one good one from several carcasses. I usually rip a PT 10 ft 2x4 to make 2x2's for the frame, and a handful of galvanized carriage bolts and fender washers, and nuts, to reassemble things into a durable, long-lasting unit. I use a quarter-round router bit to rout the handle area about 12" up from the ends, to lose the sharp edges.
At one point or another, I've brazed-up steel buckets, I've fiberglassed buckets, but I've never tried to fix a plastic bucket.
I know when I've looked online for replacement buckets I have never found one at a price I'd be willing to-pay, because I already have so-many serviceable ones, and if that one has issues, I just grab another.
If you are in a community with a dump where you have to take things, maybe hanging out there early on a Sat. morning you can scarf-up someone's cast-off. I have occasionally found units in yard sales, moving sales, neighborhood sales, church congregation sales, etc. I don't 'do' facebook, but there's that.
