Does anybody know why the raw chemical prices at ScienceLab.com are so outrages? They want $127 for 500 g of ammonium thiosulfate. Is this a medical grade? My current supplier charges €14 for twice that amount but will not ship to Florida. I'm on the look for an alternative photographic chemical supplier. I checked with Photographers' Formulary, but they only carry ammonium thiosulfate as a 60% solution and I prefer the crystalline form.