Cobra,
Not sure what type plane you fly, but "type clubs" are the logical starting place to advertise a "group buy" for something like this. (Just like the Ercoupe Club)
I am in the Cessna 150/152 (and 162) Club of America...they have thousands of members...other type clubs are also very strong and active...
Another option is airport communities...there may be a window of opportunity to buy perhaps a dozen at a time at most airports in the coming 1-2 years.
Like most group projects, the guy organizing it spends all the time doing it and many others benefit from doing almost nothing...just the way it goes!
One of the benefits MAY BE that the device is pre-fitted for that TYPE aircraft if enough of them are being produced/sold to them. There are minor things the company can do so they are easy (easier) to install. From what I have heard so far, the "10 minute installation" is simply not the case for the wingtip device. While it will still take a few hours, it is still a better deal than waiting at an avionics shop and getting a $1500-2000 bill for a certified aircraft (for most other adsb out units).
In the Ercoupe Club, they really do share the burdens, etc. Good club to be in if you have a 'Coupe.
I find being in a "type club" to be very helpful with keeping my humble 40+ year old plane flying...and there is a lively discussion about adsb and possible solutions on that site.
Mike N714AJ