As much as i agree with the sentiment that you should sell this and buy either Glock 30 or a Glock 21, that really isn't what you asked.
http://www.outdoormarksman.com/buyammo.php has American Eagle 230 grain FMJ starting @ $16.59/box if you buy 20+ boxes. Truthfully I think you'll end up paying less if you buy it at your local wal-mart/sportsmans warehouse/other big box retail store.