+1. If you are not loading your own, I would get what works best in your pistol and what you are most comfortable shooting. If you have a Wal-Mart near by (who am I kidding)...go to your local Wal-Mart and pick up some Winchester White Box (referred to as WWB). They have hundred-round value packs of .45acp ammo for <$30 per hundred. This is as cheap as you can get for .45acp ammo for the most part without reloading. If that works...stick with it. If not, try some of the other locally available ammo to you and see what you like. Depending on what you find, you may be able to get a slightly better deal buying by the 500 or 1000 round cases online, but remember shipping a 35-40lb case of ammo isn't usually cheap.For IDPA I would go with the cheapest ammo you can get that still functions and performs reliably in your gun. Most IDPA shooters load their own.