I had a house appraised in March for 410K, when I bought it. Then it was appraised for 520K in Octomber when I sold it. That was in 2010.
So most of the time, the appraisal will be alligned with contract price (believe it or not).
Also remember, if you are buying house for yourself, and your wife like the house, your kid like the house, that is PRICELESS.