Batteries for my digital camera on Ebay: $2.47
Incidentally, this is an LI-10B Olympus battery. The camera will hold 163 pictures but the battery lasts nowhere near that long since the camera charges the flash up needed or not, at last as far as I know.
I looked at memory cards for it, about $30 on Ebay but I can't imagine needing more than 163 pictures of anything - and that's high resolution. Normal resolution is about 500 pictures to a card - enough for an entire convention.
I'll be using the camera this Thursday on the same ship (Queen mary) that I'm standing on in this LJ icon - but I'll be dressed "a bit" more formally for that.