Why is my registrar charging me to redeem my domain name through RGP?

Why is my registrar charging me to redeem my domain name through RGP?

Public Interest Registry does not determine the fees that registrars charge their customers. However, the registrar incurs extra costs each time it invokes the RGP process. Registrars may charge a fee to restore a domain name through RGP at their discretion. You should contact your registrar to inquire about the fee being charged.