My “No-Cost” 3G iPhone Upgrade.

I just upgraded my original iPhone by replacing it with the new 16gb 3G model. The cost was essentially $0. How? The new 3G phone goes for $299 for the 16gb model, but I just sold my original iPhone on ebay for $300. I probably could have gotten more. It seems as though the original iPhone is a hot item in the non-US markets since it has become relatively easy to unlock the iPhone and use it with any carrier, and the new iPhone sells for around $800 USD in countries outside the US. I probably could have gotten more than $300, but I wasn’t about to fiddle with unlocking the phone. I’m guessing the person that bought my original iPhone it is going to unlock it and sell it overseas for a profit.