A property survey is a map of a property showing where structures, servitudes, easements and boundaries are located. To most buyers, being required by the mortgage company to have an updated survey for closing just seems like a waste of money. And, who wants to spend more money than absolutely necessary?

But, a survey is like insurance. The chances of you ever really needing it are slim, but if you ever do need it, you will be glad you have it. CNN Money.com has a great article about folks who wished they had a survey. Highly recommended article for Home Buyers.
http://money.cnn.com/2006/05/23/real_estate/who_needs_a_survey/index.htm