I received the fly 2/4 for P/2P offer discussed here. I'm trying to figure out the cheapest way to fulfill this (and maybe fulfill the fly three get one free offer at the same time). I'm in the SF Bay Area, the cheapest fully-refundable RT fare I could find was SJC <--> LAX for about $550, which doesn't make this worthwhile. What's the easiest way to find the cheapest possible fare in Y/B/M classes? Would this mean only selecting fully refundable fares?

Thanks!

Bill