I am from Czechia, are you going to do the course in Czech language or English? Czech ones are completely free for anyone but you usually need one or two year prep otherwise you just fail. English one might be bit pricey. At places like CTU or Matfyz there is a lot less spoon-feeding than what you might be used to.
Also, if you speak with a weird accent, no one will understand you and alone on your own you are likely to fail.