I am interested if there are any left, but what is the ROI on this and over what period of time if I only buy 1?
Anywhere I can find this info?
According to my numbers at the current difficulty and 300 MH/s it will make ~0.013 BTC per week.
-- At a very moderate 5% difficulty increase per retargetting interval (every ~12 days) you will make ROI by the end of April 2014
-- However, change that to 8% (which is much more likely) and you will make ROI in the beginning of June 2016.
This is more of a hobby mining device, you will not make any money with it
(Please anybody correct me if I'm wrong!)