Devil May Cry 4 for Windows PC is selling for 16.95AUD (free delivery). This seems to be the cheapest I've seen this game for Windows. I never bought from CDWOW so best to ask other Ozbargain users on their experience
For those who don't know about the game (and believe in metacritic), I have provided some links for the XBOX360 review and PC reviews. Both PC and XBOX360 games are identical except for some better graphics in the PC version. PC version also supports the use of the console controller
Both types of review are provided to give you different perspective of the game from a console player or a PC player
Metacritic PC reviews
http://www.metacritic.com/games/platforms/pc/devilmaycry4?q=…
Metacritic XBOX 360 review
http://www.metacritic.com/games/platforms/xbox360/devilmaycr…
I've had no issues at all with CD WoW in the past for what it's worth