323. If the taxpayer is entitled to both deductions provided for in section 322, he shall not make a deduction under subsection 2 of section 322 if the amount deductible under subsection 1 of section 322 is $1,200 or more, but he may, if such deduction is less than $1,200, make a deduction computed as though subsection 2 of section 322 applied to all the contracts entered into before 25 June 1940.