Just saw an air compressor on ebay locally to me with just a few minutes to go, put a cheaky bid on it and won. Its only a 24l tank so won't be of use to paint a whole car but it should be OK for pumping up tyres, and might just about run a 3" cutoff wheel at a push. Hopefully it'll fit in my wee garage and not deafen me too much when in use.
I bought one of those compressor things on eBay. it was missing bits and the motor made a light show like an angle grinder for maybe as long as a minute. it did cost £40. The price was a clue.