get a kazoo
Why do you want to "dose" a clarinet?
maybe from a party gift store
Fancy dress stockists might hire them
Might have to steal one. Can't get any cheaper than free.
Cosco ( or was it Sams?) sells some Clarinets that are pretty cheap..
Also if you go to a garage sale it might help, one of my classmates got her clarinet for 5$ at a garage sale.