I don't like Apple but battery is the one thing I wouldn't mess around with and buy from a cheap 3rd party vendor. Batteries tend to go boom and if it's a cheap knock-off you increase your chances. Since it will be law we will most likely get a bunch of 3rd party vendors, I would maybe see myself buying from an established battery manufacturer but not from a quick Amazon search or from the small repair shop on the corner.
Well it's a good decision. As they say, never put all your eggs in one basket, especially if you have no control over the basket.