I buy via seller uranium99 on eBay, and I get 10 (ten) rolls for about 18 delivered to the UK. He also offers 20s, 50s and 100s at even better per-roll pricing.

Of course there is a trade-off for price versus quality/consistency in this case, but I do find it hard to turn down the opportunity to be able to blow through a roll at a cost of 1.80. It's "good enough" for what I see as my level of photographic skill.