You also have to take into consideration the costs garnered by both wholesale price (i.e. the higher the quantity they order from the manufacturer = the lower the component costs = the lower the price per unit) and also manufacturing costs (how much it costs the factory, probably in China, to refit a production line, etch the PCBs, etc). Someone would have had to have went through a lot of trouble and had a lot of cash to have a production line set up, as typical Chinese manufacturing facilities charge upwards of $100,000 just to set one up.
I imagine more likely they used an existing production line and an off-the-shelf solution to mass produce them so quickly. Evidence of this is how quickly X3Jailbreak has sprung up (assuming the pic showing all of their units isn't Photoshopped). We just need to find out who is producing them and where, and what prefab unit they are using.