For the purposes of this Subdivision, the amount of the capital gain that was made or would be made on the disposal by a person (the offender ) of an interest to another person (the third party ) is the higher of the following amounts:
(a) if an agreement has been entered into in relation to disposing of the interest to the third party--the difference between:
(i) the consideration for the acquisition by the third party; and
(ii) the amount for which the offender purchased the interest;
(b) in any case--the difference between:
(i) the market value of the interest; and
(ii) the amount for which the offender purchased the interest.