Is it worth it to refurbish a 32GB Verizon iPhone 4 my self? A friend is giving it to me for free. I'm thinking about using it as a music player since I'm on T-Mobile. How much should I put into it? It has a smashed back glass, cracked front glass (not a big problem)and broken power button. I might want to replace the battery too. I hope to spend less than $100 on this. Any tips, advice on purchasing replacement parts for this?