It used to be great when they did their long running Buy One Get One Half Price offer. I used to save up my Boots points until I had enough for two rolls. It's also worth asking whether they really want to charge full price if you happen to find expired rolls; I've had some great bargains that way (although I haven't seen an expired roll for years, makes me think there must be more film photographers round here than I know of!).
Our local Boots (quite small, but not very small) has had film available almost all of the time for as long as I can remember. It's a bit hidden away.