In a past life I dealt with rechargeable batteries in general and there is a huge difference in quality with aftermarket brands. You might get a great brand or you might get a dog. The worst were ones that smoked or melted connectors as savings were quickly diminished. Often OEM batteries have built in safety features which may or may not be present in aftermarket.
Sometimes if there is an additional Dewalt tool you would like, you can find a good price on the kit with the 4 or 5 amp batteries. Just research the tool model # as often they package kits with cheaper tools. They are sneaky with this.
Our prices are more in Canada but I found a 3/8" Impact Driver (the most expensive they had at the time) kitted from a dewalt dealer (not a home improvement store) with 2 x 4Amp batteries and charger. The kit was on sale so was only $20 more than just the bare tool so a great deal for the batteries essentially.
I've seen guys selling new bare tools locally so they've bought the kits, kept the batteries and any tools they wanted and sell off the extra bare tools.
I have found the best prices on Amazon for any of the Dewalt products, including batteries.
