Who Knows
The one you noticed at the sporting good store was most likely a new production Auto Ordance carbine for 599.99
The goverment produced over 6 million of these little guys during the war. Thats allot of left over surplus but you have to take into accout combat loss, lend lese programs and other stuff were not supposed to talk about.
I would assume that the price will only go up on the older stock. Especially if your talking about one of the smaller manufactures like Rockola.