Well i've just picked one up at the whopping price of £3.99 (plus £1.75 p&p)
This one
http://cgi.ebay.co.uk/ws/eBayISAPI.d...tem=8283245701 
Just need to get some propellant to use with it now.
Do you need to thin down paints for use in airbrushes? (not more questions! i hear you say lol)