NEED HELP!!! 98 Ranger won't start?

So my friend just got a license and a 98 Ranger to celebrate. The only problem is that the thing is a boonies mobile aka truck held together by duct tape. Anyways, the thing won't start but the lights and chyme will come on when the key is turned to the accessory position. Also, the starter works but the car won't even crank. All I hear is the pinion gear in the starter moving. I checked the voltage to the starter with a volt meter and it went from 12.1 to 3.2V when attempting to start. Any ideas why it won't crank? One more thing, the car looks like it sat for over half a decade and it was bought from a redneck for $200. But it doesn't look half bad except for all the grime under the hood. Is this car even worth working on?