542. The cost to the taxpayer of any property receivable by him as consideration for the disposition referred to in section 541 is deemed to be:(a) in the case of property other than a share of the capital stock of the corporation, the fair market value of that property at the time of such disposition;
(b) in the case of a share of any class of the capital stock of the corporation, that proportion of the amount by which the aggregate of the adjusted cost base to the taxpayer, immediately before the disposition, of each share disposed of exceeds the fair market value at the same time of the property referred to in paragraph a, that the fair market value, immediately after the disposition, of such share of such class is of the fair market value, at the same time, of all the shares of the capital stock of the corporation receivable by him as consideration for the disposition.