[MikeBmusic]

The people at GC looking at used acoustic guitars typically know little about acoustic guitars in general - they are not GC's biggest sellers, and the typical sales clerks are band musicians needing a day job. So they wouldn't notice all those little things that you or I might.
Comments regarding negotiating a better price are spot on - for used gear, it won't happen there until they've had it for longer than 30 or 60 days, and its still up to a manager. If you don't like what you got through an online purchase, bring it back to the local GC for refund, you've got 45 days - but I would always have it delivered for pickup at the local GC, saves you freight cost, and if its not what you want right there at the store, get your refund immediately.
If you do that, the store is stuck with it to try and sell. Check back in 30 days to see if they still have it and you can get it cheaper.
I have got them to throw in some free extras - humidifier, strap, etc when they won't negotiate the price.