Balkan Folk run week-long courses in Bulgaria at a very reasonable cost, where you can learn to play gaida, tambura, kaval, gudulka, tapan and also learn the dances that go with the tunes.
It is a fantastic experience and truly multi-national. You can also buy the instruments there at a very reasonable price, once you know that you have a vague idea of how to play them.
I went in 2000 and would recommend it to anyone.
Mary