There is no "law of supply and demand" in the real market, only in textbooks. There is only the factor of supply and demand. Therefore, raw supply and demand is not an assumed default explanation for pricing. No one is obligated to explain why supply doesn't seem to explain price. Though, anyone is welcome to pitch as to why it might for a particular circumstance.
Other variables that are sometimes interlinked: international cash buyers, institutional cash buyers, global dollar and therefore asset and commodity value in USD (inflation), skilled labor costs and availability, interest rates, the white and blue collar unemployment rates, changing lending criteria, the cost of gasoline, regional population fluctuations, the bond market, etc.