How long ago did you buy it? When these were first imported they were only $59 and they gave the dealers a free case of ammo with it. (1440rds)
Lately i have seen them for around $175 to $225 and as far as $250. Depending on the condition they were in.
Is it a Fixed mag or ak style mag? A model D or model M? (ak mag)
Now what model it is matters too. I have an orginal wood stock norinco sks, an orginal red plastic stock norinco sks and a soviet sino sks's too. At first the soviets went to china to teach them how to manufacture and build the sks, they brought all the parts with them ahead of time. The soviet sino sks serial number is a Letter followed by 4 numbers. example; P 1234 I believe the sequence of letters runs from A to R but i'm really not sure. These are marked norinco but they were built with russian parts. Your getting a russian quality sks at a chinese price.