But surely, if you don't want the 3D display, you don't purchase the upgrade? You just keep using the 2D software.
Although the danger (for Airnav) with this approach is that they'll need to continue support for 2 versions - the 2D and 3D versions.
Until Airnav Flightwatch comes along I guess. Maybe that's the upgrade they should charge for?
So what is the answer here then? Expect the company to continue to offer upgrades for free - but don't expect them to develop the software/hardware beyond a certain point where they might need to charge for it? And what is that point, where do you stop?
It's a difficult one, and there is no way that everybody is going to be happy - not unless everything is free and that's just unreasonable. I've done work for people looking after their PC's and it does get to the point where you have just had enough doing it for free, but you don't feel you can ask them for money as they are friends. If you ask for money they get upset, if you stop helping them they are offended - it makes you just not want to bother.
Mind you, I have worked for beer before, but the top tip is not to drink it while you are actually working on the PC - lol