Hey shawn,
Where did you find yours for 49$? Most that I can find are in the 80-100$ region.
The universal DVD li-ion batteries will run you around $49 and offer longer run-times, taboot. Many different brands, likely from the same production facitily(ies):
Initial RB-270, Lenmar DVD-U9, Memorex (sorry, forgot the model #), Ultralast UL-DVDL, and I'm sure others.