As far as warranty you guys should know that sprint massively changed their policy a year ago. It used to be that if your phone broke for warranted issues you had to deal with the maker, which involved phone calls to manufacturer, RMA, your own cost to send it to the maker, waiting a month etc. Now Sprint, even if you don't pay a nickel in insurance or extended warranty, will repair or replace your phone for the first year within days -- if it is an issue covered by warranty.
I have four lines on one contract and one on another. On our three adult lines I never have ever had any kind of insurance. I put tep on my kid's phones, but only for the first two to three months of newly released phones, when replacement costs are high.
Over my 45 line years with Sprint when I calculate how much I have saved by not having insurance, and then subtract from that what I paid for replacements on ebay, less dedcuatables, I have easily saved half the money I would have spent on TEP.
Everyone is different, but in general insuring for non catastrophic loss is not wise. The key variable in the case of phone is keeping tabs on the reputable seller ebay price for excellent condition used of your model.
EG Our Treo Pros fell to $100 on ebay within a couple of months. given they were warranted by Sprint even if you paid Zero in TEP, and given the $100 deductible for non warrant claims, every nickel insurance after that point would have have been money down a rathole.
Some phones are in hotter demand, and stay high priced on ebay, some of you may have jobs or activities that expose the phone to more risk, so I do not say m calculus is for everyone. but be aware you need no insurance for the first year (typically after which the [phone drops massively in replacement cost) for warranty claims, and always keep an eye on reputable dealer ebay prices, an certainly do revisit ebay prices one year after you bought the phone if you do elect for tep or other insurance.