I (actually my wife) have multiple Mosin-Nagant rifles here. All are the original 7.62x54, we've got several thousand rounds of that
I can also safely say we did not pay anywhere near that for any of them. If you're paying those kinds of prices, you really should check out gunbroker.com. We have gotten several outrageous deals on there, like my 1911 for under $200.

Have you decoded the armory stamp on yours yet?