Well, I look forward to changing keyboards fairly often. For one thing, there are income tax considerations. With the combination of this and my usually being able to buy at or close to cost, then selling before the kb is too dated, it doesn't cost me much to change.
Of course the new instrument must be an improvement over the one I have! I can think of a time or two where it wasn't an improvement, so the change came more quickly.
DonM