Zx-10R 2006 Service costs

Moin, I gave my Zx-10R year 2006 last to the 24,000 service. The machine is a checkbook, so I brought it to a nearby workshop to carry out the service. I had asked in advance how much the service would cost. It was 500-600€ depending on the work. Today I get the bill over 1856€… Among other things 1351€ for 146 AW. Four Shims were changed on the machine, as according to the workshop all were too narrow except for one valve. a 4 spark plugs for relaxed 108€ which I also feel a bit happy. I realize that changing the Shims is more labor intensive. But 1856€ so three times as much as it was originally said. Therefore my question, has someone had comparable service costs before? And does anyone have any idea if I can do anything at all? Or do I just have to swallow it? If I had known what costs I would have called the service The cost of this is in no way reflected in the resale value.