It seems to me, from searching, that most people tend to stick to the Apple branded ones
Does anyone have experience with the ~$30 ones off of ebay? How are they?
Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)
Maybe look at my "MacBook caught fire!" thread and ask yourself if it's worth the uncertainty.
I'm 99% sure my battery is/was a genuine Apple one, but unlicensed batteries seem a very bad idea now I've seen up close what can happen when batteries go wrong.. Who knows what quality checks 3rd parties go through with their products? :/