1064 module only AU$5

[Rybags]

http://cgi.ebay.com.au/ATARI-1064-adapter_...1QQcmdZViewItem

 

Not mine and I have no use for one.

 

But $5 isn't a bad price to upgrade a 600XL to 64K.

 

Translates to about 2 quid or about $3.80 US. Postage overseas would probably be 5x the item price though.