Some very good points have already been made. Don't rush as it is definitely a buyer’s market.

Do your home work on the home and surrounding neighborhood. Drive around the area at night and especially on like a Friday/Saturday late night. Look around during the day. See who is out and about. Make sure there are no undesirable neighbors that you may have to deal with. Pay for a home inspector and have to home looked at inside and out. He/she will tell you their honest opinion about the good and the bad of the home from an outside view. Look to see how long the house has been on the market. The longer it has been then it could mean something to worry about or make the owners more willing to work out a deal. Chances are the home is not going to sell fast so TAKE YOUR TIME, don't rush. With a big price tag that a home carries you definitely do not want to rush things.

Also you can haggle with the owner and have them knock off some of the price, so you can have a new ac/heating system installed or have them install one first.