I had the valve changed on mine last summer, it too was Pierburg with the Audi rings so we can safely say they were the oem suppliers. It was date marked 6/2003 so original and lasted 14 years and 76k miles. They are not that dear, picked up the identical new Pierburg valve on eBay for £45, only difference the the revision number is now 4 as opposed to the original being revision 1.
As to fitting a 15 minute job for nimble fingers, just two small bolts and the electrical connector. Release the large clip that secures the fat air intake at the top as it bends round and park it higher up, pull the pipe off and move aside to provide access. Leave the connector on to stop it falling into the abyss when you remove it and fish out then disconnect. Likewise danger of dropping bolts into the abyss, I dropped one but luckily found it when the car was moved, would have been easier if I had a magnetic bit holder.
@A2Steve fitted one a few days ago he might have a different method or tips.
Andy
Edit. Look at the clock face production date on the one from nod to establish its age.