If you're looking at properties on a fairly regular basis, I'll guarantee you've heard the following line in the past 6 months:

"We have an appraisal from [insert date here] for $[insert amount here]."

Stop. Write it down. What was the date they told you? If it's anything other than the last 3 months, it's obsolete.

According to Shobhana Chandra of Bloomberg.com,

"Sales of previously owned homes in the U.S. fell in April and the supply of unsold properties reached a record, signaling no let-up in the 27-month housing slump.

Purchases declined 1 percent to an annual rate of 4.89 million, higher than forecast, the National Association of Realtors said today in Washington. The median price fell 8 percent from April last year, the second-biggest drop."

The average American home lost somewhere around 4% in the last 6 months. At the median home price of $202,300, your seller just lost more than $8,000 in equity. In the last year, they lost more than $16,000. Their appraisal is invalid and a new appraisal will be needed.

For all of you investors out there looking for great deals, don't listen to the hype. Do your homework.