How much do those of you who use Oxalic acid dihydrate for sublimation pay for your crystals? I note that if you get them from a company that supplies the Varrox you pay just over £10 for 75g, where as you can buy 1kg for just about the same price from a well known auction site. Are these Oxalic acid dihydrate crystals exactly the same? If you buy them for specified bee use you seem to pay a lot more than if you buy for wood bleaching etc. Is it a case of the beekeeper being ripped off again?