S&W has it for about $30 / gal plus shipping.
www.s-whobby.com Motorcycle shops sometimes have Klotz Benol. Our local Harley dealer has it in quarts and gallons, but it is more costly. I would stay away from the medicinal stuff unless I could be sure it did not have anything added. I think the term "degummed" is not well defined and is really just a marketing invention. As QwkSport said, you want first pressing.