(1) The amount of the activity supplement that is payable to a person for an activity is the lowest of the following amounts:
(a) the maximum amount prescribed by, or worked out in accordance with, the Minister's rules;
(b) the sum of:
(i) the cost of the activity, being the cost specified in the invoice mentioned in paragraph 80(1)(g) or (2)(f); and
(ii) the costs of travel or accommodation or both that are incurred in connection with the activity, to the extent that the Secretary considers those costs to be reasonable;
(c) the remaining balance of the person's activity supplement.
(2) The remaining balance of a person's activity supplement is: