We purchased trip ins for our upcoming trip in August - due to it being hurricane season (Dennis is on his way!!) we felt it would be cost effective to do so. We booked our trip via Dreams Unlimited Travel - so I do not know what company it is through. I am sure you could inquire with them about the cost and company they use and price others if needed.
Sorry I could not be more helpful - you really need to look at how much you are spending and how would you recoup that loss if something unexpected happened.
I don't always buy it for our stays in WDW. When I do... buy I get it from insuremytrip.com. They show policies and ratings from many different companies and allow you to compare the coverage. Try not to wait until the last minute. If a hurricane is emminent you won't be able to get coverage.