The R-25 can be found for 1200 if you look really hard and wait, the 308B can be had for around $1000 on gunbroker any day of the week. Both of these guns are DPMS, one is stamped remington.
I used to have a 308B and it shot 1/2" at 100 yards with match ammo. I never tried any hunting ammo other than to break it in. Keep in mind that both of these guns will need a trigger job or replacement. DPMS makes really bad heavy gritty triggers. If you want to know what those two guns are capable of, you'll need a new trigger, which will bring the price back up at least another $100. I put a timney drop in trigger in the 308 I had and it was an outstanding rifle, then again I only used it at the shooting bench.
If I had to do it all over again, I'd get the R-25. The camo is going to make it more acceptable in a hunting camp, but will also be nice if the SHTF like you're talking. It also has the A3 upper with the dust cover and forward assist. You could put a decent hunting scope on it with quick release rings, and some flip up iron sights and have the whole package that's ready for anything. I think you'd be very happy with either rifle, but the R-25 would slightly edge out the 308b for me.