A guy I know has a Nikon Buckmaster on a 300 WIN MAG. He's had to ship it back to the company at least twice, maybe three times, because the lenses keep fogging internally. Each time, they either fixed it or sent a new one. I would have give up after the second one failed. It aint worth possibly missing a chance at the buck of a lifetime to save a few bucks.
Burris is a great choice compared to leupolds. I own a pair, but not proud of it. Check out the Swift Premier Series...this is my favorite for rifles, while the 1.5-6x40 is my favorite for cantilever shotguns.
http://www.eabco.com/cgi-bin/shopper.exe?preadd=action&key=205-659M
Also the Pentax makes a good scope if it is not going on a very big gun like a 338 or a 300RUM. I got a pair of them on guns and another sitting on the floor of my gun cabinet waiting for a gun to jump on. Here is the link to the Pentax, and this site is one of the better ones for prices...
http://www.eabco.com/pentaxscopes.html