(a) Financial interest. Any purchase order or contract within the purview of this division in which any officer or employee of the city is financially interested, directly or indirectly, shall be void, except that before the execution of a purchase order or contract, the city council shall have the authority to waive compliance with this section when it finds that such action is in the best interest of the city and is in compliance with general law.

(b) Gifts and rebates. The city purchasing agent and every officer and employee of the city are expressly prohibited from accepting, directly or indirectly, from any person to which any purchase order or contract is or might be awarded, any rebate, gift, money or anything of value whatsoever, except when given for the use and benefit of the city.