Over 400 euros for 20 liters of wood stain in specialty stores

Well, how can a layperson tell the quality differences? It's really difficult. Back when we were painting the interior walls, the painter told us he only uses color XY because the cheap brands simply put fewer pigments into the "water" and save money that way. But then you have to paint three times and you only end up with more work and an uneven appearance. My dad bought a paint to paint the fence at the hardware store. It wasn't even cheap. The whole paint peeled off after one year even though it was definitely advertised as suitable for that. Now he not only has no paint on the fence, but also can't just paint over it. The quote "dirty crap" has to be completely removed first before anything decent can go on. Compared to that, 200 more seems like a bargain to me. But anyone who's clever can probably save quite a bit.

We had the same problem. Bought Consolan weather protection paint at the specialty paint store... 10 liters for 170€. Checked online at home, where 10 liters cost just under 100€. I do accept a certain premium for specialty stores compared to the internet, since you also get advice. But a 70€ premium was definitely too much for me, so I returned the paint to the specialty store and ordered it online.