Ok, got the house.
I ended up caving in and contributing $400 more, but I can't really complain - the seller was paying about $7000, the lender paid $1000, and my realtor paid $8000.
I won the battle bigtime, but at the end of the day, I still overpaid and will most likely be down $40,000 a year from now. But looking long-term, I'm still $150,000 better off than all the neighbors who moved in 2 years ago when the neighborhood was new, and as long as the area can recover to at least that level within 5 years, I'll be ahead of the game. Even if it takes 10 years, it will still have been a good purchase.
Thanks for the advice, guys.