That's a great deal for the Batman games. I got the bundle for $10 off Amazon yesterday, but that one only incuded the original version of Arkham City without DLC.

One thing I liked about the Amazon bundle though is that it also included Steam keys for both games. The GamersGate bundle doesn't appear to include Steam versions.

Some current flash sales…

The Witcher EE Director's Cut for $2.49 on Steam.
The Witcher 2 EE for $7.49 on Steam.
Torchlight II for $9.99 on Steam
Deus Ex: Human Revolution for $4.99 on GamersGate
Dragon Age Bundle for $9.99 on GameStop

*Edit* F.E.A.R. Ultimate Shooter Edition for $2.99 on Amazon.