They did a good job changing my tyres and checked over the bike. Nice guys, professional but not cheap.
I had bad experiences with other shops, even main dealers, and still expensive ... and dented my tank !!!
In the end, I bought some tools, downloaded a service manual and do my own servicing and simple repairs.
I also buy my own parts to guarantee the quality as I wouldn't trust mechanics, and I dont want to pay 1) swiss markup 2) mechanics markup.
A cbr300 should just need annual oil changes. Do it yourself for 60chf and dispose the oil in one of the many oil bins around the city ... usually where people drop off their metal / recycling stuff.
Other items like pads, fluid changes, filters are all easy. I'd expect you'll get 10 years out of your chain / sprockets. Tyres cheap to buy , expensive to fit .... maybe just order and fit in Germany.
Bigger jobs like valve shims ... I dont know who to trust.