A. Any public officer or employee of a public agency who has, or whose relative has, a substantial interest in any contract, sale, purchase or service to such public agency shall make known that interest in the official records of such public agency and shall refrain from voting upon or otherwise participating in any manner as an officer or employee in such contract, sale or purchase.

B. Any public officer or employee who has, or whose relative has, a substantial interest in any decision of a public agency shall make known such interest in the official records of such public agency and shall refrain from participating in any manner as an officer or employee in such decision.

C. Notwithstanding the provisions of subsections A and B of this section, no public officer or employee of a public agency shall supply to such public agency any equipment, material, supplies or services, unless pursuant to an award or contract let after public competitive bidding, except that:

1. A school district governing board may purchase, as provided in sections 15-213 and 15-323, supplies, materials and equipment from a school board member.

2. Political subdivisions other than school districts may purchase through their governing bodies, without using public competitive bidding procedures, supplies, materials and equipment not exceeding three hundred dollars in cost in any single transaction, not to exceed a total of one thousand dollars annually, from a member of the governing body if the policy for such purchases is approved annually.

D. Notwithstanding subsections A and B of this section and as provided in sections 15-421 and 15-1441, the governing board of a school district or a community college district may not employ a person who is a member of the governing board or who is the spouse of a member of the governing board.