Yeah, you have a myriad of good choices if willing to buy used under $500. First of all, do you want a pump, levergun, turnbolt, or single shot? That would help. But limiting the discussion now to turnbolts, you could find the following in that price range at pawn shops, gun shows, or private sellers on the net and elsewhere:
Used:
-Remington 700 (ADL, CDL, BDL, SPS, others)
-Winchester 70
-Browning A-bolt
-Fancier Savage 10, 11, or 12
-Tikka T3 / Whitetail
-CZ 550
New or used:
-Howa 1500
-Weatherby Vanguard
-Savage 10, 11, or 12 (the basic models anyway)
-Stephens 200
-Remington 770
the new Marlin is not offered in .308, I don't believe. Nor do I believe the Mossbergs are offered in .308, so Owlnmole, you're mostly right, but the answers are not *exactly* the same as when asking about .30-06.
Look for one of my bolded choices if you want a turnbolt. Then there's pumps and single shots. I can't think of any leverguns in .308 under $500 except a used Browning BLR in .308. The Marlin uses a proprietary round called .308 marlin, so that ain't .308 win.