Xfinity has two main categories for its plans: Unlimited or By The Gig. Unlimited plan prices are based on the number of lines you have under your account. You also get discounted rates based on the number of lines. For example, one line for the Unlimited Plus plan currently costs $55/month. Meanwhile, By The Gig includes however many lines you want, but they need to share a set number of gigabytes. The number of gigabytes of data ranges from 1GB to 10GB. Xfinity provides pricing info and comparisons directly on its website.