So even if you buy 12 to 24 you wont make a roi, alpha-tech will be shipping within a few months which will ramp up the difficulty
I have 20 Gidseed running at around 6.2 MH/s, and the alpha-tech stuff has not shipped yet. I will happily pay more now to have gear in my hand within a few days and running while people with pre-orders are still waiting.