I used to take calibers I didn't reload to the gunshow and try to get 1/2 the new price trading to commercial reloaders. Then trade them for cast bullets for my .45 instead of cash. I'd get a couple boxes of 500 cast 230's a year this way. Not much work but took a while to get enough brass.
Looks like .308 is $20 per 100 and .308 match is $40 per 100 average.