Seller Afraid of Demands During Escrow

[Matthew MacDonald]

The Seller and I have made 3 rounds of counter offers.  Her last offer was $420K with no credits.  I countered with $424K and $5K in credits.  I found out from the Seller's agent today that the Seller is now "afraid of me."  She feels like I have "beat her down" from her asking price, and that during escrow I will find more ways to lower the purchase price and make further demands should the home inspector find any repairs that are needed.  The only solution I could come up with was to say that I am taking the house "as-is."  

Have any of you experienced a situation like this, and how did you handle it?