Comment by lotsofpulp

The merchant chose to not offer a lower debit card / cash price because the merchant bets that people will pay a higher price if they use credit cards, so the merchant incentivizes credit card usage by asking for the same price for credit card and non credit card payment.

There are merchants that do not do this, such as Target, which charges 5% to use a credit card. Insurers/tutors/daycares/schools/healthcare providers/contractors/gas stations/restaurants/governments/utilities are also known to frequently charge more for credit card payments.

Any seller can choose to offer a lower price for debit card / ACH / Zelle payments if they want to.