no_such_reality, I totally agree, 10% is not a low ball offer, regardless of what you’re buying. 10% is just a good start point for negotiation. You never what to put in an offer too high that seller will accept it right away. You can always go up in offer but not down if you start the negotiating process. I would say low ball is 30-50% bellow asking price. Low ball is design to fish around for desperate sellers.
