17 In calculating its losses under either item 1(b) or item 3 for the cost of the purchased ammonia, the plaintiff claims the total cost of purchasing 25,843 tonnes of ammonia amounting to $9,197,710: see appendix 2 of the particulars of damage. The defendant disputes that this amount is either "additional expenditure necessarily and reasonably incurred for the sole purpose of avoiding or diminishing the reduction in turnover" as it is required it to be if it is recoverable under item 1(b) or that it is "additional increased cost of working ... necessarily and reasonably incurred ... in consequence of the material damage loss" as it is required to be if it is to be recovered under item 3. The defendant puts its case on two grounds. First it is said that the amount of the plaintiff's claim is entirely dependent upon the amount of ammonia it purchased without reference to the amount it needed to purchase to avoid its reduction in turnover. Second, it is said that the plaintiff's ammonia sales for the three months ending 31 December 2000 significantly exceed its ammonia sales for the three months ending 30 September 2000 and the three months ending 31 March 2001. This, it is said, indicates that much of the purchased ammonia did not avoid or dim 2001. This, it is said, indicates that much of the purchased ammonia did not avoid or diminish a reduction in turnover but rather allowed an increase in turnover.