Cut-rate retailers like Big Lots and Fred's put these things on sale like this all the time. It's cheaper to purchase one and strip it for the SLA battery than purchasing a new SLA battery alone. Those PR-3 Halogen lights are a bit overkill. If your good at DIY you can easily homebrew your own lamp holder that will fit in a PR-3 bulb mount. The trick is making sure when you have constructed your mount to make sure the filament in the replacement bulb is exactly the same distance from the mounting washer on a real PR-3 bulb. This ensures the focus length is correct. I simply use JB Weld to epoxy a metal socket to a washer that will fit in the PR-3 socket in the reflector and run the wires from the socket through the washer. This way you can use a lower wattage, easily available bulb in those cheap automotive lights.