The Pharmacy will charge you for the medication plus the service they provide. In most cases, dependent on the type of policy you have, the Pharmacy will directly charge your insurer.
The Pharmacy will charge a service fee of approximately €7 each time it dispenses a prescription. If it concerns a medicine dispensed to you for the first time, this amount about doubles.
These fees are meant to cover the cost of registration, administration, providing you with usage instructions, informing you about possible side effects, and checking for possible interactions with other medication you may be taking at the time.
If medication is dispensed after office hours or needs to be specially prepared for you these fees will be higher. The exact amounts are negotiated between your Pharmacy and Health Insurer.
The medication itself is also charged at a rate negotiated between your Health Insurance Provider and your Pharmacist.
You can check the average rates for a particular medicine, as well as possible personal contributions for medication at https://www.medicijnkosten.nl/ (in Dutch).
To learn more about service fees, cost of medication and personal contributions that apply to your case contact your Health Insurance Provider.