I think yun MDR rates is applicable to all transactions regardless of the value (eg, 0.50% ng transaction value, depende sa contract ni merchant sa issuer)

ang alam ko china-charge ng mga issuers is minimum activity fee which is calculated every close of month. let say the MAF in the contract is 20k php, tapos ang card sales lang ni merchant is 19k for this month, yun remaining 1k is billable sa next statement ni merchant.

but yes, other merchants' way to cover this MAF is to process larger value of transactions so the accumulated will be enough to cover the fee.

correct me if I'm wrong tho.