Markups in the retail supplement industry are pretty high. Bulk berberine HCl seems to run $5-20/kg, so its reasonable that Piping Rock can encapsulate $0.25-$1.00 of the powder, randomly check batches for adulterants, and sell for $11 and still make a profit.
Even when purchased from laboratory reagent suppliers berberine HCl is only 97-98% pure, with around 20 ppm heavy metals - ie, reasonable for a hot solvent extract from a natural source.
I've only bought chemically defined things from Piping-Rock (USP glycine, nicotinic acid, berberine HCl, D3), never enyzmes, probiotics, or ill-defined herbals. Their prices are reasonable given the wholesale costs and the direct-to-consumer model, and their glycine is appropriately sweet, their niacin gives me the proper flush, their berberine has the right colour index. Piping Rock appears to be just a new iteration of a 40 year, three generation family business, so they have strong incentives to maintain quality standards. They're a bit slower in shipping than my other usual supplement sources, Vita-cost and PureBulk, and don't carry some supplements that I prefer, like high-potency K2 M7 and algal-source EPA.
Alibaba prices and certified supplier prices are somewhat different. Pretty sure high-potency berberine (98%) is one of the more expensive supplements to get from certified suppliers ATM. Closer to $75-125/kg.
Never heard of PureBulk. Ill have to check them out.
Edited by Bateau, 25 July 2015 - 08:53 PM.