I had a renewal notice from Swinton for my homes and contents insurance which was coming in at £400 or so.
I did a quick quote on the Tesco web site it came in around £260 but after I added in the cover for £2,500 of personal possessions it came in arond £290.
A quick call back to Swinton to let them know I was getting a cheaper quote I was given a revised quote of £300 which included an additional element of emergency cover on boilers, water pipes, callouts etc worth about £80.
So, the moral of the story is spend a bit of time getting some extra quotes. I stuck with Swinton as they have always given good customer service from all of their offices. That in itself is worth paying a little bit extra sometimes.