If they are that big a b!tch they can keep what they have... First part of negotiating is to learn how to feel out which listings might be negotiable. Its pretty easy to tell if someone is gonna be hard to deal with or if they want to sell as badly as I want to buy. The art of wheeling and dealing has been lost in todays world but its one of my favorite parts of all of this.awesome!
going back to your point out negotiation skills: I know it's been mentioned before but even making an offer can be dicey because if the seller is insulted you can get blocked. Kinda hard to negotiate if your first impression ends up being your last.