I have sure there are other sites where you can buy these shoes, but I have found the prices at Amazon to be in line with other sellers and availability is usually there for me.  I own the Kayano 17 in black and now the 18 in white.  These are great shoes for me.  I walk, not run, so I am not concerned with runner's desires.  I have big feet  and need plenty of room around the ball of the foot,  Asics fit better than any other manufacturer.  Shop for these shoes a year after they come out - you'll save a lot of money and the shoe quality is just as good.  It doesn't hurt that my wife thinks these shoes look good.