Good evening Luis,
I'm not quite sure what you're trying to find out. Are you asking how much the difference is between the contract price of a property in comparison to the actual appraised value? If so, there are no statistics available for that information. Most experienced REALTORS carefully research property values prior to advising sellers of the current value range. This range is supported by recent sales data for similar homes within the same market area whenever possible.
Occasionally sellers insist on pricing their homes for well above the suggested value range. If a buyer has to take out a loan to pay for the property, their lender will order an appraisal. If that appraised value is less than the contract price, further negotiation will be necessary to resolve the difference.
Please let me know if this answers your question. If not, perhaps you could explain further and then I can respond appropriately.