Based upon the remains of the Columbus tubing decal, the frame appears to have SL or SP in the main tubes (Tretubi) and some other chromoly in the stays. I'd date it from the mid-1980s. The fork is a replacement, and the groupset is mixed (Suntour shifters and perhaps brakes, Campagnolo rear derailleur) so that hurts the value. Nice Selle Italia Flite Titanium saddle though.

For the frame alone, somewhere between $150 to $200. For the complete bike in that condition, $300 to $400.