I got my XD in 9mm a few years back. I had considered both calibers, but settled on 9 because it was cheaper and more plentiful than 40. Now I'm looking at a subcompact. I've built quite a stash of 9 but I have always wanted the power of a 40, especially in a carry piece. My questions are how does 40 compare in price and availability to 9mm today? I haven't been tracking 40 ammo the last couple of years, but I have seen that 9mm is through the roof at some places and can be very hard to find in stock. Is 40 easier to get and has the panic pushed 9mm prices beyond 40 cal? And do you think its worth it to build a new ammo cache in 40 when I have all this 9 for my other gun?