Optionalflat_Optionalflat_Same as flat_amount, but accepts a decimal value representing an integer in the minor units of the currency. Only one of flat_amount and flat_amount_decimal can be set.
Optionalunit_The per unit billing amount for each individual unit for which this tier applies.
Optionalunit_Same as unit_amount, but accepts a decimal value in cents (or local equivalent) with at most 12 decimal places. Only one of unit_amount and unit_amount_decimal can be set.
Specifies the upper bound of this tier. The lower bound of a tier is the upper bound of the previous tier adding one. Use inf to define a fallback tier.
The flat billing amount for an entire tier, regardless of the number of units in the tier.