The pics are very bad. You can't readily identify any of the components. Assuming the seller has the model number correct (which may be jump in faith, as just about everything else is wrong) the color scheme makes a 1986 model. That means a triple butted CrMo frame (not hi-tensile) with Mangalight forks. Shimano 105 derailleurs, SR SUC-100 crankest, Shimano Z-series brakes, and Shimano hubs laced to Ukai 20A (700c - they got that right!) rims. Advertised weight was 24 lbs (21 lbs would be a stretch even with the small frame) . I don't have the 1986 pricing but the 1985 version was $300 US, so figure about the same.

That appears to be the 50cm frame (Miyata measures ctt), in which case, the top tube should be 53.5cm. Hopefully the seller's obvious ignorance and numerous errors will scare off any potential bidders.