I don't think that I would want to hunt with a bottom dollar rifle, but if I had to use one I think that this is what I would recommend...

Stevens 200 rifle in .308 Winchester............$300
Nikon Buckmaster 4x40 scope.....................$125
Butler Creek Flip Open Caps.......................$0.01 with scope purchase
Warne mounts and rings..............................$40
Adjustable nylon sling.................................$10

This would be a great all around big game rifle for under $500, and if you shopped around you could probably get it cheaper than I found this stuff in five minutes.