59. Where a supplier accepts, in full or partial consideration for a supply, a ticket, coupon, receipt or other voucher (all of which are referred to in this section as a “coupon”), other than a gift certificate, that may be exchanged for property or a service or that entitles the recipient of the supply to a reduction of the price of property or a service, the value of the consideration for the supply is deemed to be equal to the amount, if any, by which the value of the consideration for the supply as otherwise determined under this title exceeds the discount or exchange value of the coupon.