Preaching to the choir - there’s little doubt I will one day try 3D Connexxion, but I’m underwhelmed by repeating hardware buttons and all that such expensive hardware e.g. like the SpaceNavigator is essentially alleged to be worth in R&D costing or ‘quality’ assurance, and it’s probably just that I’m one of those ‘lives near the Humber Bridge’ people and the hoo-har about what a thing costs when it’s purely manufacturing that’s maybe preceded by making the manufacturing equipment which is still merely the same rote production line task at it’s very essence is paid for upon completion of the contract, the work would not have been done otherwise - so recouping R&D manufacturing costs for those 3DConnexxion products must be old news already - at the price they charge, they’re into neat profit by now.
I say this because I own a mouse that has performed very well over the years - it’s r/click went sticky though and I could not see a cause or fix it, so I browsed, then found, bid on and won the Logitech Trackman Marble this post refers to, which I’m pleased to have sourced for a really low price [they were trending at £18 and I got it for less than that], it really performs just the way I like! Yet in the course of my research into a suitable replacement I looked again at the mouse I already own and knowing I’ve never paid a lot for peripheral devices - like £30 on a mouse would be sheer extravagant overindulgence, although if the performance and say, ergonomic design is there making it an easier experience to use on a daily basis, maybe it would be worth that for the years of use it would provide. So, imagine me looking aghast at the very same model mouse I bought all those years ago nowadays retailing at around £110* - what possible justification is there in that?
So, yes - competition is what’s needed, leaner prices mean more people find it accessible and continuing development naturally ensues…
*Likewise there’s a Logitech Trackball model that’s discontinued and it’s selling for an obscene amount of money, http://www.amazon.com/Logitech-Cordless-Optical-Trackman-USB/dp/B00006B9CR
There’s the possibility however that the purchase of just a ZRO2 1.984mm bearing at less than 30p will successfully replace those in my even older Microsoft Intellimouse Trackball (they can pop out during cleaning) and when I receive delivery of that minute component and fit it I may revert to using that, complete with RSI [I’ll just break from using it more often] 
