A quick google tells me i can purchase them from £4.99 - £7 by filling in a questionnaire at the pharmacist. This is what i will do from now on as it will save me money. Can't find them for sale for as cheap as £1.50
£1.50 is list price. See what I did there? I was mimicking jefmcg. You can't actually buy them at that, that's the wholesale price. But it is well known that that is the wholesale price and a lot of people say well why can't I just buy them off the shelf I'm being ripped off.
The 'filling in a questionnaire' is part of what is called a PGD (see above). You will find that it is very far from all pharmacies do them. To get them you have to satisfy the pharmacist (far more difficult than you might think given the misleading impression of jefmcg's comments). If you google slightly more you'll get a quick overview of the circumstances you can get them. Even if you turn up there may not be a pharmacist who is trained on that PGD to sell them after a consultation so you may return empty handed.
If it helps, ASDA, which has a lot of 100 hour pharmacies is the most widespread geographically that does that particular PGD that has patient friendly hours.