How much would it cost to upgrade to an iPhone on sprint?

Currently, i'm on a family plan on sprint. I have a regular texting phone with no data. There are a few other lines on this plan that have the unlimited data with smart phones. (I'm the only one without a smart phone). I wanted to know how much it would cost to upgrade to data with the iPhone 5c? On the website it costs 0$ for the phone if you start a new plan. Since i'm not on a data plan already, i assume this applies for me. Am i right?

If the other lines on the family plan are smartphones, I'm assuming the family plan that you're on is the Everything Data Share 1500/3000 plan. If so, upgrading to a smartphone will only cost you an extra $10 per month for the service. If you have or are adding TEP (phone insurance), that may be an extra cost as well… More expensive phones have more expensive phone insurance.

As for the iPhone 5C, you're looking at $99.99 for the phone itself for the 16GB model (assuming that your line is upgrade eligible). The "free" pricing online is including a $100 port-in credit, which doesn't apply to you since you're already with Sprint. I hate that the website does this, and have already submitted several complaints about it, but it is what it is. When you're viewing the phone online, there's a breakdown of the pricing along the right side of the page. Retail price $549.99, discounted $450 with a 2 year agreement (again, assuming that your line is upgrade eligible) = $99.99.