Range from the cheapest Downlights installation £240 (Nicholas Wycisk based in CR0) to the dearest Downlights installation £540 (WJ-Dlights based in CR0).
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 SE25.