I haven't read through all of these so sorry if this has been said!
Anyone in Scotland, or Glasgow in particular: there is a shop on Great Western Road called Lupe Pintos, which masquerades as a Mexican food shop but is full of affordable American goodies! So much better than those Americandy places on the High Streets which are extortionate. I got myself stocked up on pumpkin puree, French's spicy brown mustard, and Betty Crocker cake mixes for really good prices.
Hope that cures someone's cravings!