Thanks Pentaxuser and Sirius... it was reading this thread in the first place that got me thinking about how the disparity in film prices might play out across other consumables too.

Having read through the tomes of information provided by HMRC, I reckon that you're assertion that the savings might not be that great are correct.

It would seem that the only way to benefit from ordering from overseas would be to order in small quantities (you pay customs duty on stated order values of >135 and VAT on anything over 15).