IPhone with dead battery? And stuck at error 1015 in iTunes?

I got a iPhone 3g and it does not turn on by the power button. When I plugged it up it turns on and sticks at a recovery mood from what itunes said, so I hit restore and after it got over half way done it said error 1015. I have tiny umbrella installed and it says to fix 10XX recovery loop enter DFU mood so i tried that. When I unplugged this iphone it sticks at the recovery screen for another 15 seconds then shuts off and i can't turn it on in anyway unless i plug it back up. What is wrong with this thing? I paid 50 bucks for it and I'm getting really pissed. Please someone help me and not just say oh your out of your money. In tiny umbrella I did hit exit recovery and the phone rebooted and stuck at the apple logo for another 15 seconds then rebooted and stuck at the recovery screen right again. I think someone tried jailbreaking it or something and messed it up. Anyways someone please help me. Btw I have let this phone on the charger for over 12 hours so if the battery is still good it should have a charge? Maybe the battery is shot and just holds for a few seconds from when I unpluged it? I have looked into getting a new battery and how to put it in (which looks easy) But is it worth it?

Http://www.itunes-error.com/how-to-fix-itunes-error-1013-message/