Instructrions state $500 month for API

Is this correct? $500 per month to receive and API key? If so, this plugin is useless for small stores? It’s a waste of time to install according to this http://www.dutycalculator.com/api-center/Get-started/

https://wordpress.org/plugins/dutycalculator-calculate-charge-import-duty-taxes-at-checkout/