I'd just like to say how despairing I am that I cannot source less than 10% BP in the UK. For a product that I should be able to get on prescription, I have to pay 31 dollars. This is using the cheapest postage cost offered, which gives me a delivery of "between 2-6 weeks" - which is the difference between running out of BP and getting it in time to use consistently. I cannot order in bulk, not even the larger size bottle of BP, for fear of getting charged import duty. The price I am paying for a basic medical necessity seems crazy. My doctor tells me there is very little difference between 10% and 2.5% in terms of skin reaction but clearly this site says different. It looks like I'll have to find out.
I too am in the UK.
Apologies if you have already explored / are aware of these options, but you CAN get less than 10% BP in the UK. In fact (before I started using Dan's 2.5% BP from amazon.COM) I was simply purchasing Quinoderm BP 5% from Boots (admittedly they seem to stock Quinoderm 10% more commonly but they would order in a Quinoderm 5% for me if they didnt have it in stock and it would be in within a few days. They don't have Quinoderm on the shelves, you have to ask for it at the medicines counter (but you don't need a prescription to buy it).
Also if you want BP on the NHS you could ask if your GP will prescribe you any of the following - they are listed in the BNF (which is a list describing all medicines that can be prescribed in the UK)
Acnecide = BP 5%
Brevoxyl = BP 4%
Duac = combination of BP 3% and clindamycin 1% (antibiotic).
Lastly, having used quinoderm BP 10% and 5% and now having used Dan's 2.5% BP I have to say I definitely prefer Dan's 2.5% BP. Its a gel which seems to absorb into my skin more easily than quinoderm. The 2.5% doesn't dry out my skin anywhere near as much as the 5 % or 10% and you get a lot for your money with Dan's 8oz BP tube, I'm sure its going to last me months.
PS I just use the Cetaphil cleanser and lotion (from Boots) rather than Dan's ones (haven't tried them as i find Cetaphil works great).
Hope that's of some use to you