My response used to be "About half what its cost me"
... whilst looking at adverts recently, and thinking how glad I was that I've hung onto mine over the years, as there's no way I could afford one/justify the expense now, how terribly expensive they are now, Rocket Goldie rep? thats just an old shonk with clipons!blahblahblah...I realised that these days it probably is worth what its cost me over the years.
I don't know how I feel about that.
I still preferred it when people asked "Wottleitdoo?"
Cheers,
Iain