Good source for Black & Decker replacement part?

[Uncle Wig]

Thanks, but in this case I don't think used is the way to go. The one that came with the sander just started falling apart after a while. The highest price is about $11, which seems high for a tool that sells for less than $30, but I'd rather spend a bit more and not deal with a questionable online seller.

Here's the sander:
http://www.amazon.com/Black-Decker-RO100..._3?ie=UTF8&qid=1409687821&sr=8-3-fkmr1&keywords=black+%26+decker+dust+bag+387111-00