>The author, clearly not a developer, doesn't seem to see the potential for high cost in making a software change
Agreed, one should be fairly close to the dev team before coming up with estimates. Other red flags: "government agencies" & "So the MTA could make a small software change that only applies to the Credit Card Only machines with limited effort"
It is almost certainly the case that there is no readily available mechanism for easily changing the price on credit card only machines without changing it on cash + credit card machines. Presumably changing the default pricing structure would have to change both, which would cause the problem that either a great many machines would suddenly be providing $0.95 worth of change for everyone paying with a $20, or everyone would need to start carrying around nickels.
Clearly it is more work than a simple price change to create a new user interface that asks whether you're going to be using a credit card or not before displaying the prices.
Agreed, one should be fairly close to the dev team before coming up with estimates. Other red flags: "government agencies" & "So the MTA could make a small software change that only applies to the Credit Card Only machines with limited effort"