Two Year Price Comparison on Super Smartphones by PCWorld:

A brand new unlocked Nexus One, without a contract, will run you $529 at Google's new Android phone store. Right now, for all practical purposes, the phone works only on T-Mobile within the U.S. So let's assume you grab the carrier's $79.99-a-month unlimited talk/text/Web plan, which is currently available without an annual contract.

For consistency in our comparisons, we'll say you're going to use the Nexus One for two years. Add up the phone's cost plus the plan over 24 months, and your wallet is now $2448.76 lighter.

An iPhone 3GS, on a comparable unlimited AT&T plan, would run you $3798.76 over that same two-year time span. A Motorola Droid, on Verizon's unlimited plan, would also cost $3798.76. It all comes down to the carriers' plans: Both AT&T and Verizon charge almost double what T-Mobile does for unlimited talk, messaging, and data service. It's all part of the deal, and it's all money of your pocket.

All considered, then, the Nexus One -- even with the unsubsidized handset pricing -- ends up costing you $1350 less than its contemporaries.