Assume that a local bank sells two services – checking accounts and ATM card services. Mr. Done That is willing to pay $8 a month for the bank to service his checking account, and $10 a month for unlimited use of his ATM card. Ms. Been There wants to pay only $5 for a checking account, but will pay $15 for unlimited use of her ATM card. To keep this example simple, assume that the bank can provide each of this services at zero marginal cost

Once we have made these assumptions, what is the question?

To determine the optimal pricing strategy for the local bank, we need to identify the preferences and willingness to pay of Mr. Done That and Ms. Been There for each service (checking account and ATM card).

Let's start with Mr. Done That. He is willing to pay $8 per month for the bank to service his checking account, and $10 per month for unlimited use of his ATM card. Since both services have zero marginal cost to the bank, the bank can charge him these amounts for each service.

Next, let's consider Ms. Been There. She wants to pay only $5 for a checking account and $15 for unlimited use of her ATM card. Again, since there are no marginal costs associated with providing these services, the bank can charge her these amounts for each service.

So, the optimal pricing strategy for the bank would be as follows:
- Mr. Done That: $8 for checking account + $10 for ATM card
- Ms. Been There: $5 for checking account + $15 for ATM card

By setting these prices, the bank can cater to the preferences and willingness to pay of both customers while also maximizing its revenue.