Thanks for your input guys! I've left the brand out since for myself is not important at this point (beginner biker, no brand favs). But for full disclosure, it's a Bianchi Intenso model. Purchased in a LBS, so I don't doubt the origin.
I wasn't too clear about the "appraising" part: I'm actually thinking of buying this, not selling; however, the seller is a friend and asked me to come up with a price. He's an experienced biker, upgraded this year to a BMC etc.
From my price research online, hard to come up with a conclusion. There are too many variables involved even for similar bikes, ads are incomplete, model year is usually not listed, etc.
I was thinking around 25-30% of original price would be fair. Especially considering that bike will need wheels replacement soon (front hub is moving laterally, probably needs new bearings; rear hub developed a click which again I suspect bearings or at least the freehub).