Here you can see my Maruka/Maruichi.

Did you have a look at the shop of Maksim?
He lives in Europe and is a very friendly guy.
He has some great japanese naturals.

Just yesterday I bought a Shoubudani from him that I am looking forward to very much.
His prices are highly acceptable and he can help you with your search.
I suggest you send him a message,
because you should not pay more than 400€ for the best japanese natural I can think of
You can get equally fine stones for much less if you are willing to accept inhomogeneties in colour,
or small chips on the back and razor-stone size etc.

Here