agree. I also quoted DfT regs and put something along the lines of "£1 is extortionate, and questionable pricing in a monopolistic situation"

btw, I'm using ziplock bags bought in the US. Couple of dollars for a box of 20in a RiteAid, Walgreens or similar chemist/open-all-hours store. Maybe not helpful if you don't visit the US, but worth a walk down the street if you happen to be there.