Do you have an example or two of this price difference? I've purchased chemicals for silver and cyanotypes over the last year and have compared the prices between B&S, Photoformulary, and Artcraft. In general,my price ranking (decreasing) is in that order. With the chemicals I've ordered, I don't recall a case where B&S is less expensive than PF. Prices may have changed recently, however.
Is it just me or are the photographer's formulary prices much higher than bostick & sullivan's? Have I missed something?
Why not just shop online and compare prices listed in their online catalogs?
You may want to check the prices at Art Craft Chemicals as they seem to be the least expensice on most chemicals.
Of course shipping expenses may be a factor to think about as well.
I can't say enough though about the level of customer service B&S has when you ask for it. Michael Jacobsen has given good service but isn't as savy about alt process knowledge as B&S are. I don't shop as much at PF since shipping from Montana to the eastern U.S does play a factor. There are times when none of these suppliers can provide you with a specific chemical. I've even had Dick Sullivan tell me where to find items they don't stock.
Also don't forget the Chemistry Store, Bryant Labs or Tri-Ess.