I wouldn’t say its one of Klein’s “lower models”…yours was the top of the line road bike at the time—a few years later they transitioned to internal cable routing and split the Quantum line into Pro and Race. Compared to the later models these earlier Quantums like yours were a bit heavier but the ride and responsiveness was still very much there. The fat chain and seat stays are marvelous. Value wise the components are mid-range at best but are consistent, and the color is a popular fluorescent and doesn’t appear too faded (unless its been repainted in which case that drops the price.) I’d estimate $700 on eBay and $500 locally? Others can correct me if I’m off (I’m biased as I have Klein frames piling up to sell.). I should add…it looks like a 55 or 54? If smaller than that the price would drop a bit. Most in demand are the 57/58