Ah. I just checked, and that is indeed the resolution of the 4k monitor I'm currently using. So I would guess that standard is pretty common!

That’s also why 5K monitors are more than 2X the price of 4K ones at similar sizes. I have a 4K with those dimensions that I bought for $400, an LG 5K would cost at least $1200.

I think the price is more about where on the adoption curve those technologies are. 4k is pretty mainstream these days, older tech and produced in high volumes: ergo cheaper. 5k is still pretty new, mainly constrained to higher end products, and sales volumes are lower: ergo more expensive.

5K 27" monitors predate 4K 28" ones, but the supply was basically monopolized by Apple from day one. I can get an affordable 5K monitor, but unfortunately I have to get an iMac CPU unit to go with it.

And they took away target mode so your only compute option is the processor that came with it. That still annoys me, I’d like to drive my perfectly great 5K display with an M1 Mac mini.