How much is iPhone 4S insurance if it's stolen and you can't report it?

Basically I can't report the phone stolen for personal reasons, but how much would I generally need to pay for a new one with insurance on the same plan?

Well if the phone is under contract, you will still have to keep paying the month fee until the contract has ended. To end the contract early, contact the telco and ask how much to cancel the contract. It will be at least the value of the rest of the handset payments (ie a $70 monthly plan might include $15 a month handset repayment) plus a penalty payment of a few hundred dollars. Otherwise you can buy a new handset outright (an iPhone 4S will be a few hundred dollars) and get a replacement sim card BUT you'll still be on the same plan and repaying the cost of the stolen handset until the contract ends.

Whatever your deductible is - usually $200.