Inspection at 38,000 km after 3 1/2 years

Arona 1.0 TSI 115 PS The usual maintenance work was carried out, so far so good. But the prices seem to me a bit exaggerated. Pollen filter = 57,20 €, installation and installation = 12,80 €, plus VAT, together 83,30 € gross. Oil 0W20 23,61 €/ltr. I accept, as well as the usual invoice filling small collar for approx. 25,– €. As “additional work” stands spark plug change on the invoice. Per candle are calculated 35,19 €. In addition 76,80 € for 3 spark plugs change. He changes candles 182,37 €, in addition comes the VAT. Makes then brutto 207,02 €. That seems rather happy to me. I am glad that I don’t have a 12-cylinder. Which candles are the right ones here? In the net I find e.g. BOSCH Double Platinum for approx. 11,50 €. As a classic car screwdriver I certainly don’t need an entire hour to change 3 candles on this engine. These are works that I do myself after the expiry of the warranty period.