Range from the cheapest window sill replacement £280 (Constantina Locksmith based in N15) to the dearest window sill replacement £560 (TICO Builder Solutions based in N5).
Comparing carpenter & joiners estimates for replacing a window sill 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 window sill in N7 by posting a job with HaMuch and we will send it to carpenter & joiners in N7.