I see what your saying, but if you have an account then you don't have to buy it all at once. You can go in every other week and grab 3 or 4 bags on your account. You can still get a discounted rate as a high volume buyer that way, and your feed never gets old.
Only problem with that is your...
Ok, and that will continue to rise quickly if they are only 5 weeks. How much is this feed in your area?
So now you can shop around for prices and see what the best deals are. You can tell them you'll be buying 300 pounds of feed now, and will be needing even more every month after that. They...
Well, besides using a no spill / no waste type feeder (several plans for home made versions of these are on this site) you can save money by buying in bulk. My local feed mill sells All Flock, Layer, Grower, Starter, Ect all for about $15 per 50 pound bag.
However, they give bulk discounts for...