Audi A4 Cabriolet sales price?

[TCTVR]

Time for my better half to say goodbye to her 2009 TDi final addition with 69k on the clock and in excellent condition. She has fallen in love with having a TVR, either a Chim or Griff and it has taken ages to convince her of this I have a reasonable appreciation of the TVR market but not so close on Audis. Any ideas what the asking price on the Audi should be set at?

Thanks

TC