It's only $199 from Apple, and it doesn't void your warranty.
guess Apple taking a loss when replacing battery so design moves forward.
I recently gave my original MBA away, it still works great and has original batt in it, working at 90% capacity. 54 months, no issues. If the next round of laptops hold up like that, who cares what a batt replacement costs? But why *would* anyone go the third party route?!