Not really luxury items, unless you go for one of the more exotic ones.
I have gone through so many rubber dome keyboards - they just feel mushier and mushier, it gets harder to push certain keys requiring a different amount of force across the keyboard, and this leads to unergonomic typing practices.
A mechanical keyboard should last considerably longer than a rubber dome keyboard. The switches are rated for 50,000,000 key strokes each, and the keycaps are easily replaced.
I also use mostly MX blues, and the tactile feedback take me back to when I learned to type on electric typewriters and older computers, and my typing does seem to have improved since I switched from robber dome.
So although notably more expensive than rubber domes, I would not consider them luxury items.