This is really a noise fact that must be stopped...
Beta testers invited by Google to tests Gmail (the new free e-mail service) also received invitations to give to another person, and many of them are selling on Ebay this opportunity (with prices that starts from $61)... for example, the account for hackers@gmail.com now is asking 200 dollars! Currently there are about 190 invitations for sale on Ebay. 
This is terrible!!! Apart that I think only a stupid person could buy NOW addresses at this price for a BETA email address (and for a future FREE service), this type of actions must be stopped immediately!
Google, I hope you could do something! An example of possible action? REMOVE all the accounts of people that are selling them.
If you are a privilege user for testing Gmail, you're not authorized to do speculation with it. 