While no knowledge of the later cars, this is the way it is going. Just too complicated. Firstly, have a chat with the spares guy at a VW dealership. Same car?? so maybe they can provide some additional advice.
The $1000 from Audi may prove to be cheap if you need to run around for weeks / months to get a key. Can't work out why the locksmith didn't do your non proximity key. Did he say?
Surprised you haven't found a locksmith in Canberra but I haven't had the need so can't help there.
C5 RS6: Sportec, Milltek & Wagner -- B5 RS4 : modified -- B5 Audi 1.8 quattro 132 Kw -- 2007 VW Touareg TDI -- UNIMOG 404 TLF8