Alternatives to a $300 key for a later C5 A6 (2004)?

[Mark R]

The remotes can be programmed using VAG-COM.  You'll need to bring all of
the remotes to be programmed so as to de-authorize the missing remote (and
to make sure you don't de-authorize a good remote).  The key portion itself
is dealer only AFAIK.  I thought they all ordered the keys from VAG, but
maybe some mill them out themselves.  The parts department can order just
the insertable shiny metal part of the key- a roll pin is all that holds it
to the remote.
Mark Rosenkrantz