Hi Pavel,
Thanks for taking the time for leaving us a review.
For our apps on the DC platform, the target group is larger organisations, this is reflected in the user tiers, with the lowest tier being up to 500 users, similar to the base Confluence on DC.
For smaller organisations, while our DC product works well as a solution here, if the pricing is an issue it might be useful to take a look at our cloud version instead that has more flexible lower user tiers: https://marketplace.atlassian.com/apps/1221322/refined-for-confluence-cloud?tab=overview&hosting=cloud.
Let us know if you have any more feedback or questions for us, feel free to reach out at https://support.refined.com/.
Best regards, Team Refined