Westbury Tyre and Exhaust Centre 01373 827200 on the industrial estate outside of town. The owners old man is Ex Army and while he doesn't do a forces discount his service is excellent and his prices are the cheapest around the Wilts area.
www.blackcircles.com are good-I use them for my tyres which aren't particularly cheap and I've always had excellent service from them-they use local garages and work out cheaper getting the tyres from them than going to the garage that Blackcircles use (which is bizarre).
I would recommend etyres but they are very very poor and therefore I'd strongly suggest you don't use them-I had to get my money refunded after they messed me about for a week or so saying they could sort out my tyres when they couldn't. It took 3 phonecalls for them to refund my money. Avoid like the plague-they claim to cover most of the UK when in fact they don't-I've just checked their website and they still claim to cover the area where I live plus 20 miles around it-err, they don't.
If you're a member, Costco does bloody cheap tyres. Mine were quoted as Â£300 in Kwikfit, went for Â£175 in Costco. True, you have to pay a annual membership, which is Â£28, but even if you only buy 3 tyres, you've saved yourself the cost already.
Another suggestion for Black Circle, get a price from the site for your tyres, then when you choose a local garage to fit them, give the garage a call direct and get them to price you direct. If its more than what Black Circle charge (which it normally is), tell them the price you got through Black Circle and see if they don't knock that price down a little bit more. I got an extra 10% off 4 tyres doing that.
For the tyres I wanted (not cheap) I found that kwik fit were actually cheaper than black circles. As an aside, the bloke who ran the kwik fit did me two puncture tyre repairs for free (should have been Â£40) so long as I went back and got my 2 tyres off him.
I bought my last tyres on line, excellent price, and fitting was done at a fitting station of my choice. They clearly paid the fitting staion well enough because my treatment there was first class. You need to plan a few days ahead, but I will certainly be using them again. Just try a bit of googling, you get to choose the make etc and there is often a better choice than you get in the likes of Quick fit, whose doors I will never darken again.
I have just had 4 tyres fitted 215 45/17 and spent ages trawling the net . I decided against some of the cheaper budget end as some of the reviews suggested they were about as much use as a chocolate teapot.
In the end i went for some called Kumho . I had never heard of them but if you google them they are very well rated and cost me £65 a corner all in. When you compare that against say a michelin they were about £110 a corner.
So far the tyres have been brilliant very sticky in the dry and wet! I would highly reccomend them.
If you are happy with part worns, there is a tyre recycling guy in oxfordshire that does tyres from £5 depending on the sizes.....he can even post them for £8 a tyre (only really worth it if its a big sized tyre) PM me and I will speak to him, its only a private enterprise.