The Legislature hereby finds that many persons and families of low or moderate income, as defined by Section 50093 of the Health and Safety Code, cannot afford to purchase housing in the conventional housing market. The Legislature also recognizes that counties occasionally acquire residential property requiring substantial rehabilitation prior to being deemed habitable. Since maintenance of existing housing stock and the extension of opportunities for homeownership are desirable objectives, the Legislature declares that the public interest would be well served if counties were empowered to sell such residential property at less than market value to such persons and families of low or moderate income, on condition that the purchaser rehabilitate the home and reside therein for a specified length of time.