@sato Hello!

The final price depends on the country (due to VAT), but it is roughly 8€ for PRO license. You can check your local price here:

https://play.google.com/store/apps/details?id=com.guio.guioapp

This is the easisest way to purchase a single license.

Alternatively, for multiple licenses we offer different purchasing options (not via the Google Store).

I hope this answers your question.

Best regards.