(1) Subject to the time limitations in subsection (2) of this section, the following documents relating to an agency's real estate transactions are exempt from public inspection and copying under this chapter:

(a) Except as provided by chapter 8.26 RCW, the contents of real estate appraisals, made for or by any agency relative to the acquisition or sale of property;

(b) Documents prepared for the purpose of considering the selection of a site or the acquisition of real estate by lease or purchase when public knowledge regarding such consideration would cause a likelihood of increased price, including records prepared for executive session pursuant to RCW 42.30.110(1)(b); and

(c) Documents prepared for the purpose of considering the minimum price of real estate that will be offered for sale or lease when public knowledge regarding such consideration would cause a likelihood of decreased price, including records prepared for executive session pursuant to RCW 42.30.110(1)(c).

(2) The exemptions in this section do not apply when disclosure is mandated by another statute or after the project or prospective project is abandoned or all properties that are part of the project have been purchased, sold, or leased. No appraisal may be withheld for more than three years.