The letter of intent allows for all facts and figures to be verified so that the buyer understands exactly what he or she is getting in the property. If the buyer finds something that he or she can not accept, or something not originally expected, he or she can back out without any recourse or punishment.
Beware of an individual or group of people who call themselves Investment Bankers or a Buying Group. When they cannot provide you with personal financial statements or a financial statement from their company, you have a very slim chance of ever closing the transaction. The seller should have a copy of the financial statement from the buyer attached to all offers.