Have you guys seen the SOG packs at WalMart? Great quality, good zippers. The barrage looks like a 5.11 72 hour rush, but its only $45. Worth taking a peek at when you go by to purchase some 7.62 x 51 ammo for $.49 a round.
drago packs at academy sports or amazon are another good solution on the cheap...almost a direct copy of maxpedition falcon 2 packs but only $50....stitching is not as clean as the more expensive pack but made of 600 cordura.