A couple of observations:
1. If you put the bike in the classified section, there might be somebody from another part of Vulcandom who is looking to club up (or down) to a 900. It may already be there, I didn't check. I'm not in the Forum Police squad...
2. If you still have the OEM seat, put it back on the bike and sell the Mustang seat. You'll easily get 2-300 bucks for the seat, and it will not add (or subtract) 300 bucks from the going price of the 900. JMHO. Same for the windshield. I wouldn't bother with the throttle lock.
3. Your asking price is about $4,000 too low.
If you snap the chalk line a little higher in your asking price then the bike won't sell as quickly...and you can keep it longer...
Seriously though, it's a good lookin bike, and the price is resonable.
Good luck buddy.