another woman who needs help!

Hello together, I’m here for the first time and have a big problem with my beloved Omega (3L, 155kw, year 97, 99.000 km)! I was in Sweden by car (was great, as always!) and last Monday my display suddenly showed that there was too little cooling water in it. We replenished the water, drove a few kilometers and it was less again. You could also see that it dripped out of a hose. We then went the next day into a small workshop (there was not v iel, very lonely area). The master took 2 hours, found the leak and repaired it (but the man spoke only Swedish, so I don’t know exactly what he did). We drove about 100 km the next day and the display said again, too little water. But there was no drop to watch. We are back in the small workshop and the guy then opened the water tank, pulled the gas lever and the water started to blubber and swell out. He then said “big, very lonely area”. problem!” We are then to the next Opel dealer (200 km, car ran great, hardly any water loss). He did the same thing, the water bubbling, he immediately said cylinder head seal, the car is not allowed to drive any more meters. Then he put such an instrument on the open water tank and measured the pressure, which was probably normal. I left the car in Sweden and got a rental car. The ADAC brings the car back in the next few weeks. My question: What does it cost unfae hr to have such a cylinder head seal installed at the Opel dealer? Is that still worth it for my car? It is otherwise absolutely top! I would be very happy about an info! Do me extreme worries… Thanks in advance!