Hrm, dunno, can the seller tell you what the name on the drops-outs are? If they are Gipiemme, which is my guess, then it would indicate a model on the lower end of the Bianchi spectrum. It looks like a mid-range model made of the Columbus Chro-Mo tubing that was made for Bianchi, nothing really special but nice enough.

I think that for 300$USD you can do a lot better, something at least made of SLX or 531S even. But, it is the classic celeste and it appears to be in pretty good shape, so he will probably get 3 bills for it eventually. In other words, you are paying for the name/colour, not the build of the frame.