If you’ve ever spent an afternoon wistfully clicking your way through the Craigslist “free” section — pondering all you could do with an extra this or that — you’ve sampled a certain seductive sweet taste. Beware: the California Materials Exchange is crack to Craigslist’s cocaine. It’s eBay on steroids, Urban Ore for colossi. A state-sponsored recycling program, CalMAX facilitates the transfer of bulk, odd, and industrially useful products for wholesale and discount rates, and sometimes for free. So, looking for extra cubicles? How ’bout a free 1000-gallon asphalt-emulsion tank? Or 7,500 pounds of apparel, including 300 women’s black twill pants missing only the waist button? That’ll cost you a paltry 10 grand, but for someone with a plan — and a lot of storage — it could be just the thing.