I bought my Sigma DR-28c new in 1983 for around $650 at a guitar shop in London, Ontario. After a minor adjustment, the action is low, fast, and light. I normally string with extra light coated strings and am really impressed with how well it holds tune. I've had a few professional musicians play my guitar, including Kix Brooks from Brooks and Dunn, and all were very impressed. One player offered me $800 and I believe he was low-balling me (he knows guitars!). Although it's hard to find info on it, I believe it's design is based on the Martin D28. It's a beautiful guitar and I will never sell it! I am not sure just how many were even made between 1980-83, but it seems rare.