Hi,
AvantGarde Bk is made by the Bitstream foundry. AvantGarde is from
both Adobe and ITC as far as I know, so you should check who made it
and under what EULA. There's also third AvantGarde under the name
Corel Avalon, which is rather old (predecessoror the AvantGarde Bk).
It belongs to the classification of Geometric Sans Serif fonts, so you
should find alternatives in that classification, i.e. Futura.
Identifont has a small list of 'similar' fonts:
http://www.identifont.com/find?similar=ITC+Avant+Garde+&q=Go
When you have some kind of Font Management software you should be able
to lookup the foundry from where it came. You can also try the Windows
File-Properties dialog and see the tab Details.
And here's something else:
Rubicon Font Library has a Geometric font called Wanted:
http://www.rubicon.ca/samp_p31.htm
Maybe they have offer an attractive EULA for only 12 USD :-)
Cheers!