you can get good quality batteries online for less than $1 a piece
I found a source awhile ago for the $1 Cr123 in my opinion the $2 name brand batts were much brighter. A quick google search will get you tons of places to buy them.
At first I bought the rechargeable kind from radio shack and I almost burned down my firehouse. SO, the inexpensive disposible batts from now on.