Upon receiving a request from the county assessor, either upon his or her initiation or at the direction of the board of county commissioners, for special assistance in the county's revaluation program, the department of revenue may, before undertaking to render such special assistance, negotiate a contract with the board of county commissioners of the county concerned. Such contracts as are negotiated shall provide that the county will reimburse the state for fifty percent of the costs of such special assistance within three years of the date of expenditure of such costs. All such reimbursements shall be paid to the department of revenue for deposit to the state general fund. The department of revenue shall keep complete records of such contracts, including costs incurred, payments received, and services performed thereunder.