A friend just gave me a Sigma GCS-2 that was made in Korea. It is in excellent condition, other than having sat in its case for years (I assume w/ no climate/humidity control). She said to send her a check for what I think it's worth, but I have no idea. I want to be fair, so can Sterling or someone out there tell me what the fair market value would be? According to Sterling, Korean Sigmas were made between 1984 and 1993. Thanks. G