The pay-it-forward product has been built on $1 increments. This permits GoGenerosity to customise the donation amounts being displayed in a standardised way. We have also found it is instinctive for customers to change donations in $1 increments and has been built with this in mind, allowing customers to modify amounts in a preferred way.
The way the product quantity appears is depending on the cart theme.
For example, some carts will display a $5 donation as x5 $1 donations in the order summary.