For any informal request reasonably likely to involve a fee in excess of fifty dollars, the custodian shall provide an estimate of cost to the requestor prior to assembling the documents or records and the requestor shall confirm in writing his or her acceptance of the cost estimate and agreement to pay. The custodian may exercise discretion to waive or reduce any fee required under this section if the waiver or reduction of the fee would be in the public interest.
SDCL 1-27-36