If by a "few" thousand, you mean 3 to 4k, then that's really not that much as used bikes go. That said, it's enough to make certain parts worn a bit, e.g., the chain, cassette, brake pads, and cables. The crank itself would likely be fine at that mileage.

Granted, I like my Bianchi. If you like the fit, handling and ride of the bike, then I think it would be worth getting even if you have to replace some of the parts. Depending on what's worn, if anything, it would still likely be cheaper to replace those parts than to buy an entirely new bike. But only you know your budget.

If your bike shop does suggest replacing some parts, start with the chain. If a new chain doesn't skip on the old cassette, don't replace the cassette yet. A lot of shops will tell you that you need to replace both at the same time, but I (and a lot of other people) disagree. If the new chain does skip at all, replace the cassette at that point. Also replace the brake pads if they're worn. That's not an expensive fix. New cable housing is also not expensive.

In any event, keep you chain clean. You'll get more life out of it, the cassette and the chainrings.