Range from the cheapest replacement of a toilet float valve £50 (South London Gas and Heating based in SE19) to the dearest replacement of a float valve £85 (1977 - Denham Plumbing and Gas based in SE26).
Comparing plumbers estimates for replacing a toilet float valve in the cistern tank 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 to replace a toilet float valve in SE21 by posting a job with HaMuch and we will send it to plumbers in SE21.