$0 Option for Payments

Hello.

Till date, I have experienced discomfort with many plug-ins concerning payments, like Supporter, MU-Affiliate, Upgrades, etc.

All of these plug-ins doesn't have 0 in one of the values. With all of the plug-ins value starting from 1, it doesn't allow me to charge/pay in cents, instead of dollars.

Suppose I wanted to charge $0.80 in Upgrades plug-in and since there was no 0 as value, I had no option but to increase the price to $1.

I wonder why all the coders made the minimum value to 1. Why not 0?

Thanks for reading my suggestion.