Re: Plateau in 3, 2, 1...
The crappier your quality the more likely folks will go elsewhere for their next purchase.
Which is exactly why manufacturers like Logitech will continue to do well. After their 5th cheap Chinese £10 keyboard from eBay fails, people will realise that, in the long run, it's better to spend more money on something better built.
To be fair, there are lots of manufacturers out there who make perfectly good mechanical keyboards with knock-off Cherry switches these days, so you only really need to splash out if you want genuine ones. People will always want to upgrade to something nicer though.