One-time imports of products, contacts, and categories are completely free.
Up to 5 regular imports (including suppliers, connection accounting systems) is a single price of 15 € / month.
For 6 or more imports you'll pay additional +25€, so in total / max you pay 40€ / month.
There is no charge for separate import of orders, categories, and customers.
You can view the current list of active imports and their charges in Wallet.