Actually, it looks like an interesting project with an extremely very good profit margin!
Unlikely that a USRP unit could be a $100 item as originally suggested. Cost could be minimized if the board was simply cloned, sold with exchangeable or multi-tuner expansion and without technical support.
A major issue for distribution would be that it would be highly improbable to obtain Part 15 FCC approval for transmission for a wide spectrum device. Would the technology still be of interest if it were developed as a receive only project?
If your going to repeat what they have done, the price alone will be too high.
If you can find someone to do a mass produced ASIC, then I suspect a $100 device might be possible.
The Transceivers are not a problem, as you can S/W disable them, and also S/W control just what bands they operate in. In effect, the S/W you release with the parts would have to comply with the FCC regs

Also, there is the WhiteFi standards coming out that are wide band friendly.
The key to this is ASICs... or at least mass produced ones. Once you get this under $100, these things replace AM/FM radios, TVs, WiFi routers, CBs, FRS, police radios, cell phones... you get the idea.
The key will be to release S/W control code. Thats where you obtain FCC licensing.
Or at least as I see it...