Should I purchase the flight insurance when I buy an airline ticket from Priceline? Thank youf for your input.?

I would just buy the ticket direct from the airline website. You probably get the same price and cut out any possibility of confusion by dealing direct with the airline. "flight insurance" can mean a lot of different things, but never buy insurance. I travel a lot and it pretty rare for me to miss a flight or not be able to go. The few times it happened I have always been able to apply the price paid toward future travel. Sometimes they charge a change fee and sometimes not. In the long run I have come out ahead.

Those sort of offers rely on your laziness - you're likely to just take out the insurance while you're booking your flights, rather than make a separate exercise out of comparing prices etc. You're pretty much guaranteed to get the same cover cheaper elsewhere. But whether it's worth bothering if you only stand to save a few measly bucks, that's your call.

Always buy travel insurance from a source other than where you purchased your flight, cruise, vacation package, etc.