Notary fees / cancellation reservation. Land charge

Hello everyone,

my notary is not really getting back to me at the moment - so I am posting the question here:

We have a Rückauflassungsvormerkung for my grandmother in our land register. But a Grundschuld up to an amount X may be registered with priority. Now I want to increase the amount X. Can someone tell me what costs occur at the notary and land registry office for this? The amount is between 50 and 100 TEUR

Is it about a new land charge or does grandma have to consent? You can simply use an online calculator for a new land charge. They are almost accurate to the cent. If grandma has to consent, it becomes more complicated (and more expensive) - but I am not familiar enough with the notaries' fee schedule for that.