The prices paid for property at auction sales are not usually true indications of value. The sale may be an involuntary one, as for instance, a sale resulting from the foreclosure of a mortgage. The property may be bid in by someone having a claim against it and the full cost to the purchaser would be the bid price plus the amount of his claim. The public is not attracted to such sales unless the property is especially desirable. Voluntary auction sales are usually widely advertised and there is more competition in the bidding. A large crowd and spirited bidding may in some cases produce prices in excess of actual value, although even under favorable circumstances sales may be made at low prices.