(b) the amount obtained by subtracting, from the amount of the expenditure determined in accordance with paragraph a, the amount by which the aggregate of all amounts each of which is a contingent amount of the taxpayer in the year in respect of the expenditure exceeds the aggregate of all amounts each of which isi. an amount paid by the taxpayer to obtain a right to reduce an amount in respect of the expenditure, or
ii. a limited-recourse amount for the purposes of section 851.41 that reduces the expenditure under that section to the extent that the amount is also a contingent amount described in this paragraph in respect of the expenditure.