2 or 3 years shouldn't be a big deal. I used a tire from 1985 on my truck back in 2011-2012 and it was like new, no dry rot or anything (it was kept in a barn). I think as long as they aren't exposed to the elements they don't age all that bad. Like Scorpio said though, it would be nice if they gave you a small discount or a coupon or something.