#1 - Value is in the eye of the owner on this one, I have domains I would not take $10,000 for that most would not pay $100 for.
#2 - It's equally as annoying when you send someone a starting offer and they counter with something totally outrageous because in their skewed logic they think all their domains are virtually priceless, I am a big buyer, and that will turn me off a domain quicker than anything.