3000 h check - who? where?

Hello to everyone on the forum.

I'm fairly new to gliding - finished my ABC in Australia in the beginning
of this year but I'm originally from Bulgaria where I live at the moment
as well.

I'm looking to buy my first glider at the moment and noticing a lot of
gliders for sale near the 3000 h check (Astirs in particular as I'm
looking for one).
I know the 3000 h check is a fairly big thing but I don't know where it
could be done in Central Europe and how much would it cost?

Any help and information would be appreciated!

All the best.
Ivelin