PayPal

You can purchase a bundle of 100, 500 or 1000 SMS text messages. Your SMS balance will be increased by 100, 500 or 1000 SMS text messages.

Note: you must be a subscriber to SMS Mac.

Bundle of 100 SMS ($10):
        
Bundle of 500 SMS ($45):
        
Bundle of 1000 SMS ($85):
        

You can also pay using eSellerate.