Tricia,
as you are quoting in dollars, i would assume you have used the US website, (.com) they do not normally come with the insurance's included in the price by default. The .co.uk site will probably have all the insurances added in ,except the pick up/airport taxes.
However , have you tried the site that is advertised on this forum www.uscarhire.co.uk , they offer very good rates and come with insurances.