The legislative body may, by resolution, specify terms and conditions under which the city agrees to repurchase the bonds. The legislative body may secure a letter of credit or other instrument to secure payment or repurchase of any bonds, and the resulting costs, including costs of initially securing, maintaining, or making any payments arising from the exercise of, a letter of credit or other instrument, may be treated as incidental expenses. The legislative body may engage a remarketing agent and an indexing agent, subject to terms and conditions agreed to by the legislative body, and the resulting costs may be treated as incidental expenses.