Range from the cheapest Downlights installation £290 (Stranders Electrical based in HP19) to the dearest Downlights installation £455 (Corbec Electrical Ltd based in HP21).
Comparing electricians estimates for Downlights installation 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 installing downlights by posting a job to electricians in HP20.