I think you'll find that it's because it is sold by local hardware shops in small quantities, and each link in the supply chain wants to make a heafty profit. Most oil companies have pulled out of selling it at service stations, you don't get the Esso Blee Dooler any more.
Is it about time it should included in almanacs that it getting hard to get in the UK and it is expenive. Inspite of all those grounded jumbo jets not guzzling av-parra. it must be going somewhere. Anyone know where i can buy 20 gallons of the stuff?