You can now buy and sell Google Glass on Swappa:
“If you resell, rent, lease, transfer, or give your device to any other person without Google’s authorization, Google reserves the right to deactivate the Device, and neither you nor the unauthorized person using the Device will be entitled to any refund, product support, or product warranty.”
Found here: http://www.google.com/glass/termsofuse/
Google has also made it clear though that they are not deactivating anyone’s sold Glass and do not plan to:
Q. Is it OK for Explorers to try and sell their devices online? Will you disable the devices if they do this?
A: The Explorer program is about taking Glass out in the world and seeing what’s possible with the technology. We hope our Explorers are excited to do just that. While it’s against our terms of service to sell your device, we don’t plan on disabling any Explorer’s device.
Found here: https://sites.google.com/site/glasscomms/faqs
If we can help someone who bought Glass recover some money by re-selling without ridiculous eBay fees, or help someone explore Glass who can’t afford a brand new unit, then we’re happy for Swappa to provide a safe place for that transaction.