brand new is not avaliable, Audi can get you a company rebuilt one.
if UK price is 6000/-GBP, thats very expensive, Buying from Grmany would be cheapest.
Searching, buying a used one from ebay is best option from a salvage cabriolet.
locally repairing in Pk is not a option but is a disaster, It took me a few tries on Toyota to get it going right, Audi is way out of question.
Go to salvage yards and ask , can also try in Dubai scrap yards.