If you mean Russian SKS rifles made in the 50's stacked on the shelf and now for sale in the us? They run as the other fellow said $250-350, range, but understand, these are not new, not used maybe, but made in the 50's is not new!
You can get a military used SKS at Kiesler's Firearms for $150 in store. Try www.kieslersfirearms.com, they might have some in stock. I've never ordered anything online from them though. I live about 25 miles from them so it makes more sence for me to go to the store. They're located in Jeffersonville, Indiana.