Range from the cheapest Fix a leak £240 (South London Gas and Heating based in SE19) to the dearest Fix a leak £380 (1977 - Denham Plumbing and Gas based in SE26).
Comparing plumbers estimates for Fix a leak gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes for fixing a leak in your home by posting your job to plumbers in SE21.