I actually recently switched to a safety razor from Wilkinson Sword (those blades mentioned, are supposed to be used with safety razor), and was enjoying it a lot. The razor itself is not too expensive, yet it improved my shave quality, decreased a price-per-shave, and skin irritation after shave (omitting occasional but very rare nose cuts). I use a blade in 1.5 weeks with ISANA blades from Rossman, and pay about 2€ per 10 of those, can definitely recommend.
The only downside: you can’t bring those on any airplane, so I carry a cartridge razor to get at least some shaving done when traveling. And immediately I do that, I get razor burns :(((
There is also Vinted, which operates across EU.
Asides, in Poland Allegro Lokalne exists, which is making an attempt in the same market.