No exchange of County-owned real property shall be made for privately owned real property, unless the value of the privately owned property is of equal or greater value than the County-owned real property. If required by the County, the private proponent of an exchange must provide, at his or her cost, an independent appraisal of any proposed exchange, said appraisal to meet the reasonable satisfaction of the County. Upon written demand, either party may require the exchange to be consummated pursuant to RCW 36.34.330. Nothing herein shall require the County to exchange property under any circumstance.