It is a case of "the right horses for the right courses" in terms of postage
Absolutely. Delivery and prices always vary so much that it definitely makes a lot of sense to check as many sources as possible. The websites that I like the most are the ones that tell you actual delivery without having to sign in/make accounts, so much better and more user friendly.
Sometimes Jessops can be worth considering (there, I said it!). Their prices are higher than most but you can order on-line then get them to deliver to your nearest store to pick it up - so no postage charges at all.
"People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.
or you could go to any local place that develops or sells film and ask if they have any expired film.
Most places usually half the price as soon as it expires, but it still should be good to use... and if you're really lucky you can get a nice big box for dead cheap