Witcher 1 $2.19 AU http://www.gog.com/game/the_witcher
Wiedzmin 2 $4.29 AU http://www.gog.com/game/the_witcher_2
GoG seems to automatically charge you in $AU unless you clear cookies and use a VPN or overseas proxy, but the last time checked they were one of the few companies that doesn't rip us off on currency conversions. The GoG rates seems to be exactly the same as the Xe.com rate.
Realms of the Haunting is quite good too for $2.20 (66% off), providing you can handle old world graphics. most modern Indie games released have abyssmal graphics anyway, so this shouldn't be a problem unless you normally only purchase pretty A List titles.