Stampe - some form of dealer's policy, methinks?
SuperOwl - most brokers will not need to discuss terms with the underwriters if the pilot who you wish to add to the policy of your aeroplane can show suitable times on similar types. However - if they do not have sufficient or any experience then the broker refers to the u/writer who will generally stipulate a higher premium for the new boy or will increase the excess for that particular pilot.
I seem to alternate between the same two brokers year about for both aircraft that I am responsible for arranging insurance.
Light a/c generally have the premium made up from two key components - hull value (ie - a/c value) and third party liability.
Hope this helps,
Stik