I recently purchased a used iPhone 3Gs for my parents which was apparently jailbroken/unlocked (I didn't know that). It worked fine but when I connected it to my computer/iTunes to put music on it, iTunes prompted me to update the firmware to 4.3.5. Since it was a used iPhone, I figured it would be good to erase all data on the iPhone before updating it so I did that. Once the iPhone was wiped, iTunes tried to update the firmware but I got an error message. Now the iPhone is stuck in restore mode and I don't know what to do. I found someone online who jailbreaks/unlocks iPhones who said he could fix it for 40$ but I would have to go to his apartment and I'm not sure if I want to do that yet...

Any help would be greatly appareciated. Thanks!