Compared to the last 5 years, there is hardly any surplus .308 on the market. It's been widely available, and very inexpensive, for about the last 10 years, as countries that used to issue .308 rifles (mostly the FAL, but the G3 in a few cases) have moved to 5.56 or 5.45 weapons.
All that surplus is definitely drying up, though, and once it's gone, it will be GONE. In many countries, .308 is no longer in (military) production at all. Plus, many countries have signed the UN's "Small Arms Non-Proliferation Treaty" and have passed related laws in their countries to ban the surplussing of military ammo. Billions of rounds have been burned instead of being exported as surplus. I've been warning people of this for several years. Back when I started, few people believed me. A lot more believe me now. Many others still have their heads in the sand because they don't want to believe it.
In the 80s, surplus .30-06 was everywhere and was cheap. AND much of it was high-quality genuine US surplus. People thought it would never dry up. Try to buy some today.
-Troy