I made the mistake of paying a company £144 recently for a 'drain survey' which basically told us nothing other than that our gulleys needed repairing. It was accompanied by quotations for this work which were clearly extortionate prices.
I phoned around some other relatively local companies but was still getting high quotes. I then called North West Drain Services Ltd. run by John Makin, based in Bolton (Tel: 01204 689677 / Mob: 07756631110). He was good enough to provide a reference for his company/work and I was more than satisfied. His men completed the work over 2 days, doing an excellent, thorough job and leaving everything very tidy and in good condition afterwards.
Best of all, he quoted me a price that was around a third of the other quotes I received and he stuck to that price, despite the fact that extra unforeseen work had to be included. If, like me, you are unable to find a satisfactory drainage company more locally, I would highly recommend using North West Drain Services for an honest, reliable and excellent value for money service.