For all services available we ask for 120,- EUR per hour net of tax (we also accept German DM, the old "Mark der DDR" or the even older "Reichsmark", but all with their appropriate exchange rates) with a minimum charge of 30 minutes for each on-site visit.
It doesn't matter if we are working during the day, at night or during the weekend. Just as is doesn't matter where in Berlin you're located (you pay for our services, not for driving around).
For services outside of Berlin we ask for payment on a time and material basis.
Telephone support and remote administration in limited volume is at no charge (but not to no avail).