RCW 36.34.060: Sales of personalty.

Sales of personal property must be for cash except when:

(1) A public auction sale by electronic media is conducted pursuant to RCW 36.16.145;

(2) Property is transferred to a governmental agency; or

(3) The county property is to be traded in on the purchase of a like article, in which case the proposed cash allowance for the trade-in must be part of the proposition to be submitted by the seller in the transaction.