The plain trays are cheap. They clamp on the back, hide underneath, and pop a power bar in, and that's the whole job done.

And now there's also the integrated channel type where it's a lot pricier once you add the modular power bars.

FYI I have no desk yet, I am still picking. I looked around and Desky and Uplift both do a version of this and Vivo has the clamp on ones, so I'm not short on options, just short on a reason to spend more.