If you want to unlock costumes fast, then use arcade tag battle. It will unlock costume for both character at the same time. If you don't have DOA 5 DLC, then that is the fastest way to unlock it.
http://www.gamespot.com/dead-or-alive-5/videos/mila-command-training-dead-or-alive-5-gameplay-6396382/
http://www.gamespot.com/dead-or-alive-5/videos/rig-command-training-dead-or-alive-5-gameplay-6396385/
Or just here:
http://www.gamespot.com/dead-or-alive-5/videos/platform/xbox360/ for others...
Well, I just went by my Gamestop to pay full for my DOA5 Exclusive CE and they said that will will be doing a Midnight Release on the 24th. So is anyone going to one? I'm happy that it's popular from where I lived.