Need to buy Metallic Battery Back cover for Samsung Galaxy S3

I own a White Samsung Galaxy S3 bought in October 2012.The phone hasn't experienced any bumps or falls,but still its battery cover which is a scary glossy stuff has many hairline scratches and swirl marks,which looks downright pathetic.I have seen some metallic battery covers on sites like ebay,but they are very expensive.I might order it if I dont get any substantial suggestion from you guys.Still,I haven't purchased any thing related to gadgets without taking your opinions.
So do advice me if you find a nice alternative to it....

My choice-
Battery Cover for Samsung Galaxy S3 SIII GT-i9300 Metal Silver (black frame)