DeWalt Tools, Replacement Battery question?

Earlier this morning i found a vendor on ebay, that i purchased a new, genuine, DeWalt lithium-ion battery out of a combination kit, for the price of $104.00, plus the mailing.
Guess, I'm comfortable with that price, so i paid it, and now just have to wait on the mailman to get it to me.
That price is at the lower end of the hundred dollar plus, prices that they are advertised at.
Thank's everyone for your input, with my question.
Appreciate it.