(3) In any civil action to recover on an open account, account stated, note, bill, negotiable instrument, guaranty, or contract relating to the purchase or sale of goods, wares, merchandise, or services and in any commercial transaction unless otherwise provided by law, the prevailing party shall be allowed a reasonable attorney's fee to be set by the court, to be taxed and collected as costs.
The term "commercial transaction" is defined to mean all transactions except transactions for personal or household purposes. The term "party" is defined to mean any person, partnership, corporation, association, private organization, the state of Idaho or political subdivision thereof.