Griffith's Shaving Goods also carries thuri bouts, although they're quite a bit more than 45 Euros. Either way, far cheaper than any branded Escher. The Greek Vermio stones they carry are also excellent hones for the money. For example, here is a full-sized Vermio for $89: http://https://www.griffithshavinggo...nt=12749415620. Matt says they finish even finer than thuris. I had the smaller one myself and got some great edges off it before selling it to a former Scout I've managed to brainwash into our cult.
You can also find thuris on Etsy some times. I just got a yellow-green one this week from one of our members, and early testing seems promising. Let us know what he ends up with.