Although I have only been in real estate for about 8 years, I have been in Sales and Marketing most of my adult life. Someone taught me early on that the best deals were the ones where both sides could declare a WIN!
If both the buyer and the seller leave the settlement table happy, that is a great transaction. If either side walks away feeling like they got treated badly, who wins? No one.
Let's consider the buyer. Negotiate hard, but always remember that your new neighbors were probably good friends of the seller. If they feel "taken advantage of", how welcome will you be when the neighbors get together for the next Happy Hour? This is a market that has definitely favored the buyer side of the transaction, but sometimes I feel it has brought out the worst in many people. Get a great deal, but be grateful and know when enough is enough. Be gracious and give ground so the seller can move on feeling happy you will be the new owner of their home. It does matter.
We just sold our own home recently. We put a lot of sweat and money into renovations and updates. It was our "model" home. The buyer really loved what we had done and expressed his enthusiasm several times. Yes, he negotiated hard, but he was very respectful and I believe we were as well. We came to the settlement table with both sides feeling good. That made it much easier for me to leave my home and be happy it was in good hands.
In other cases, I have had both sellers and buyers forget when to shake hands and work together for a successful transaction. This also applies to both the Buyer's Agent and the Listing Agent. Don't be the one who is remembered for a stressful and difficult transaction, please.