They are expensive, and its a shame there isn't more competition.
If you can find one, I really like the Dell P2415Q. It's been around for ages (the 15 in the model name refers to 2015), and if you can find one, they're 1/3 to 1/2 the price of the LG 24", but at exactly the same size/resolution (and thus PPI). It seems like Dell either has, or is in the process of discontinuing this model though, so it might be hard to find now.
One thing to keep in mind is, a 'retina' of Hi-DPI screen, regardless of whether it's running at native 2x or even at a 'non-optimal' scaled resolution (e.g. if you wanted the screen resolution of 2560x1440 on a 4K 27"), is going to look much better than any non-Hi-DPI display.
I would generally recommend a display that can do Hi-DPI, because it gives you a lot more options (i.e. choosing different scaled resolutions on a Hi-DPI screen is very doable, and isn't likely to negatively impact most tasks (i.e. things where pixel perfectness isn't a factor), and gives a much clearer picture. If you had one at the time, think about the difference between the pre- and post- retina iPhone/iPad screens. It's exactly the same scenario.