Big Agnes has, I understand, a lifetime warranty on their pads (check their website to be sure). REI now gives you only one year. In that case, after the one year, it's the manufacturer's warranty that is more important. Buy the pad (and everything else) where you can get the best price (google shopping can help). Which of course may be REI with the current sale!

www.campmor.com often has lower prices, especially when selling closeout models. Another place to check.