Found a really good, reliable garage locally a few years ago.
Which one? - I use G+N on Fields Farm Rd. He's old school and knows to test drive the M, rather than check on the rollers. £45 for a test. The only time I don't use him for my cars is when I get a free voucher for Halfords, or if I think my van will need welding.
If you don't DIY, try Dave Wallis on Huss's Lane. He doesn't MOT, but he will check and repair. I don't know his price to just check and MOT.
If you want a cheap MOT, there's always Chatsworth (£40). Use him if you will need welding, but don't use him if you want pretty welding. Ideal for a van.
I've just found a place that will test for £20 (I've not used him yet), but I think the car would have to be pretty spot-on to get done for that price, as only brakes and a quick look could be done for that price.