My 1996 Audi A4 2.8 quattro auto came only with one key (no fob).
I assume the car originally had the remote key fob.
a) Where can I get them (sources)? Cost?
b) Do they need to be programmed? Who can do it? Cost?

 

you need to go to the dealer and a key for my 2001 a4 was around $180 and it costs like an extra $50 for them to program it.

 

That is for the the 230 reasons you mention NOT an option.
But I first need to know if my car originally had key fob or plain keys (they offer blanks for $12 on ebay, but cutting new keys from worn old keys is NOT the recommended solution; keys from VIN would be better).