I was lead to believe from an insurance broker friend of mine that they are putting 3rd party F&T up to more than fully comp to try and stop people going for the cheap option, and instead getting fully comp.
He also told me that insurance companies use repeat insurers as 'Sucker policies' as they don't shop around and their higher premiums off set the newer customers cheaper deals.
Once I heard that I started shopping round every year, and every year I get it cheaper than staying with existing insurer.
SO, in short, don't be a sucker, shop round and play them off against each other, or you may as well wave good bye to hard earned cash.....
Sermon over.