HELLO. yes coureses are quite expensive.you can make a lot of progress with personal tutoring. For oyur improvements... Lot depends on you and your time for studing...and on the other hand Basel doesn't permit you to hear and practise High german. everbody speaks Swiss german! so if you can attend a one to one personal training and try to exercise with german environment...
I still suggest Rainer or Anita of Academia. Thez are really qualified, and if you push they push.
Nice time