In cases of contracts for the lease, rental or hire purchase of products or services, or in the case of contracts which do not specify a total price, the basis for valuation shall be:
(a) in the case of fixed-term contracts, where their term is 12 months or less, the total contract value for their duration, or, where their term exceeds 12 months, their total value including the estimated residual value;
(b) in the case of contracts for an indefinite period, the monthly instalment multiplied by 48.
