Meant to add this last night. I was at Tesco Opticians yesterday, and got fitted for new contact lenses as my prescription has changed. They're doing a special offer at the moment, 30 dailies for £10, both eyes (not sure about other prices as I only use Focus Dailies All Day Comfort).
Of course I tried buying more but the offer is only restricted to one month's. Not sure if it applies to other varieties of contact lenses. Another good thing about Tesco is that they're open late, til 7pm or 8pm most nights. In my Tesco Extra you can make appointments for Sunday too.
The offer runs out soon but can't remember the exact date! Sorry! The offer doesn't seem to be on the Tesco Optician's website either.
I normally use daysoft but this is cheaper, and a well-known brand.