[kazinator]

Any added margin that makes your product more expensive, that does not go into your pocket, is bad for business.

It's basically a form of someone stealing from you.

The user was willing to pay $4.50, all of which you could have had, but $0.50 went to a parasitic third party.

We can look at it from the point of view of the transaction between the buyer and seller being arbitrarily robbed of $0.50.

We can also look at it from the POV of the supply-demand curve: fewer units are sold of the more expensive product.

Both these effects hit you: you're selling less because it's more expensive, without you getting any more of the extra per-unit revenue.