I would not be surprised to see standard, good condition, RHD, early (1970's) air cooleds to be regularly selling for over £5,000 in a couple of years time...
Like Draigflag, I've had some tempting offers on my own cars...I bought one last year for a ''crazy price'' and was offered £1,000 more than I paid within a day. It's not for sale though, which in itself seems to push the price up!?! Put simply, they are amazing cars and with the abundance of (cheaper) spare parts they are a much more affordable option than the Fiat 500s and even more fun!