Currently looking for price suggestions for 50x50 pixel buttons/icons

I was thinking of making them 3 - 5$ usd / 300 - 500 CSC I'm struggling with how to convert that to SP as I want to offer SP as a payment option. Any help appreciated.

these are cute! i'd say 500 csc is a good price c: most the time i see people use the conversion of 100 CSC = 10mil sp, so it'd be 50mil sp!

Thank you~ I thought that was how SP converted to CSC but wasn't sure.
This helped alot thank you