I've had the stuff for multiple years and as long as it doesn't evaporate, it's fine. I have some in my fiberglass tank that must 5 years old and I'm very sure if I go out there tomorrow and try to start it, it will start on the 1st or 2nd try. I may actually do that tomorrow and let you know.
I used to get it at the local airport, but they decided not to sell it in containers any more, but there's a Sunoco station in Warrenton VA that sells all sorts of 'racing fuel'. I get the 110 because it's the cheapest, $60/5 gal. I use it in my Stihl equipmnet, it runs better and doesn't clog up so much. Wonderful stuff, smells good too. It's got the blue die in it just like avgas. But when it evaporates, it leaves no trace other than the blue color which just washes off next time. The Stihl dealer also sells the 100 octane, but they want $80/5 gal.