You can be sure of the fact that there are a lot more people interested in such a gadget than the ones that have had their say in this thread. Especially if you can keep it cheap...
It's just that most people who have nothing useful to contribute don't post anything.
Now, about not being sure there is enough market for your device... that's called doing business... it involves risk...
But I'm quite sure that if you made up a batch of 100 (properly designed, light, and precise) units to sell at 99 bucks a pop they would be gone in no time with a little advertising... Did you ever look at the rates for a banner like the ones that appear at the top of every RCU page? It's not all that expensive... and maybe throw in an add or two in a couple of popular magazine and you're ready to go...
But that's only my view on things of course...
I'm going to talk to the fellow in our club that made the altitude data logger to ask him what he thinks about all this... maybe I can talk him into building me something and I can play test pilot...
