All joking aside...start reloading!
Any decent match fodder is going to run you >$1/round these days and it doesn't take long for that cost to add up. While the initial investment in a quality reloading setup, including components such as bullets, powder and primers, can be daunting, but for most people who want to shoot high quality ammo with the utmost accuracy potential for their rifles without breaking the bank...reloading is the ONLY way to go. You can recoup your initial investment in equipment in fairly short order and once you have that investment paid off, all you are out is your cost for components and time to crank out quality ammo in whatever quantities you want/need at any given time.
Aside from reloading...the Federal OTM ammo that Elfster mentioned is pretty good and can be had for <$1/round if you can find it in stock. MidwayUSA and others carry it fairly regularly for ~$180/case (200 rounds) plus S&H which usually gets you to just under $200 for 200.
Also, since you are trying to find the best deals, have a look here at the Gun Deals page for 7.62/308 ammo.
gun-deals.com - User-Submitted Gun & Ammunition Deals As you'll see, they offer user-submitted links to deals on in-stock ammo, which you can sort by bullet weight, cost, etc. If you plug in your zip, it'll give you delivered cost as well.
Good luck!