To give you an idea of price, a couple have sold recently on ebay:
Boxed:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT
ZX Sport with full electrics:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT
This one is not due to finish for a couple of hours:
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT
hope that helps