Range from the cheapest replacement of a toilet float valve £25 (Erjon Dulaj based in N16) to the dearest replacement of a float valve £100 (Cube gas based in E2).
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 E8 by posting a job with HaMuch and we will send it to plumbers in E8.