Just to give you a heads up, I've got a load of chip based items on eBay. All starting prices are £5 or under, so get involved bidding!
Commodore 64 console - http://cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1156
Cynthcart Setup - http://cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1156
Casio SA-20 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1156
Yamaha PS-20 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1156
Megadrive - http://cgi.ebay.co.uk/ws/eBayISAPI.dll? … 500wt_1156