Saruma makes a good point about checking the
RedBook. While the overwhelming majority of these fakes that I've seen have fallen within the date range of regular issue coins, a small percentage does not. One such example that I bought for $3 in order to educate fellow collectors in my area is an 1879-S "
Trade dollar" - a non-existent date.
While I concur in principle with the thought of staying away from these counterfeits, the reality is that they are everywhere. Isn't it more practical to educate our fellow collectors? Coin clubs everywhere need to periodically devote some time and discussion to this problem within our hobby, passing around examples at meetings in the process.
Getting back to the point Saruma made, I often have an older copy in my car for reference when traveling. The Chinese counterfeits are more likely to be encountered, touted as genuine, in flea markets and antique malls.