I pre-drill all holes.
XPVC cut to size= $198
50ft of 3" heat tape= $105
PT 2" x 4" frame= $5
Screws (coated #6 decking screws 1 5/8" long)= $10
2" casters= $16
60 V-18 tubs= $271
That's the total soup to nuts cost= $605. That's $10.08 per tub final cost. Commercial racks are are selling for $20+ per tub plus shipping or picking up at a show.
I am not including the router cost in the build, because that will be used for many more projects. I've never used any glue, but simple PVC pipe glue would work. Wheels are for convenience of moving for cleaning in the shop.
Half way done mounting the shelves this morning: