I recently went to look at some pvc that someone on Craigslist had for sale, and it was rather heavy. It was much heavier than I thought it would be. I keep hearing people say that pvc racks are so much lighter, but if I built a rack out of this I would think it wouldn't be that much less than a melamine one. Or at least the same as wood.

Is there different weights to pvc? Is XPVC lighter than regular PVC? How much lighter?