Just my opinon, if you buy a clap-trap Mk III .303 or whatever for $150 and put $150 into it you'll end up with a $200 gun that doesn't shoot all that acurrately, is a pain to reload for (.311 dia bullets), and no one makes a decent scope mount for.
Save your money if you want an accurate .308, shop the pawn brokers and gunshops. Many guns get sold in the months after Christmas when bills and taxes are due- it's a good time to shop with cash in your pocket. Savage 110's and Remington ADL's can be had for $300 and you'll be light years ahead of any $300, .303 you are likely to find.
Don't waste your money on junk.
Merry Christmas!