sfrider 

No problem - look at the bar tape, chain, cassette, brake pads, tires, etc. If it all looks new, it's new - doesn't matter if it has been ridden. If I can't tell I treat it as new. Otherwise, I'd talk down the price based on the wearables and any potential blemishes. (Although to be fair, if there are nicks in the paint or other blemishes I'd have them order me another, unless I get a deep discount.) I don't buy bikes with stock wheels, pedals, or saddles, and would have the seller put on different bars anyway, but even if the bars stayed on I'd have them put on my favorite bar tape (2mm Fizik Microtex) anyway, or do it myself. It still has the same warranty as a bike straight from factory assembly. Even if it has been ridden 500 miles that really means nothing other than the usual wearables, and either those are replaced, or the bike is sold without them, or it's discounted. (Basically, I don't pay "new" prices for used tires and chains. That's just silly.)

I bought a car off a lot with 140 miles on it, and paid $47k for a $55k configuration. This is for a brand where a "deep" discount is 6% and invoice is at 7%. The car was what I wanted, was spotless, and about $2500 less than one with 10 miles on it. It doesn't matter in any way to me if someone else drove it 100 miles or I did it the first week. I also know this dealer doesn't do unattended solo test drives, so they could vouch for it not having been abused.