I don't think they are obtainable from Bal. Keep your eye open for the right size on Ebay or Bonanzle. Every once in a while someone will put one up.
that's funny, they've got all these fakes on there, but oh no, don't sell a dustbag! WTF???????
wow, i wonder why you cant sell dust bags on ebay??
Maybe it's so the fakers can't buy the real dust bags for the fakes?