I know very little about bikes but parts of that frame resemble my Nishiki very closely. I have almost exactly the same parts. Forged Suntour dropouts, Dia Compe brakes, Suntour Cyclone, etc. I also have the same 27" aluminum Araya rims with Shimano hubs.

My bike is not near as nice as yours though because mine was stored outside and not well cared for. I think $125 was very reasonable.