A software system for gradually purchasing a real estate property, comprising a gradual acquisition plan on the part of a purchaser of an estate which is registered in the name of a legal entity represented by quotas; the quotas are transferred by the bank, owner of the legal entity holder of the estate, to the purchaser, according to a certain gradual reacquisition plan; the method includes reacquisition phases on the part of said purchaser of quota or portions of it through the payment, to the bank, of monthly installments, each including the quota value and relative interest; said quotas can be exchanged by an electronic system in order to exchange the estate with another property by mean their respective legal entity.