Not sure who told you this but it is not correct. I did a couple of test quotes on Confused.com at the time to see and there were big differences. Several hundred pounds or so in fact.

My insurance before this was around £700. On renewal it went to about £750 (with a different company) but checking quotes on Confused with the £20k or so claim added (instead of the £1k that they actually paid) came out well over a grand from the same companies who had previously quoted around £800 or so.

M