I’ve recently been seeing a lot a ad for sub $50 honeycomb back plates.
I don’t currently use one at all. Would I likely see any benefit from using a budget plate over no plate on a 10w laser used mostly for cutting thin ply and balsa for model making?
Bit late to the party here, but if you are cutting material they are very handy.
They help cutting by allowing the beam and air assist an unimpeded exit, but also make a really good hold-down surface. With a bunch of odd powerful magnets you have a very versatile clamping system for all sorts of material.
It is worth shopping around, the real kicker is shipping costs. These are big and heavy, and I used an AliExpress store with a European warehouse in the end. At 65 euros this bed is actually the 3rd most expensive thing in the picture, after the framekit and laser module.
I brought an alixepress one and found all of the same benefits as you.
Indeed logistics costs are a problem
I bought my K40 second hand and it came with an aluminium cutting bed and yes they are essential for cutting but for the previous laser to my K40 I made my own bed bed using a ferrous metal grill as magnets do not stick to aluminium and I made these corner tools using 3 magnets to hold the workpiece on the bed and in the place I want it so I have placed a ferrous grill over my honeycomb bed and use the same tools made from 2.5mm birch ply.
I have to rebute a couple of these claims. A honeycomb bed sounds like it would be as good as sliced bread… However the fact and operation show it’s not a very good choice.
It’s nice to have the material supported, but I engrave watercolor paper on my sheet of rolled steel…
The air only has the kerf of your laser, usually <0.1mm, so there is little air getting through and the output side is a fine stream of pressure.
The honeycomb fills up with cut debris, where it condenses and is very difficult to remove. It is also responsible for starting most fires within lasers. Look at any of the posted photos, unless it’s new, the honeycomb is coated with flammable debris.
Even where the beam does strike the metal, it’s reflected and marks the underside of the material.
You totally lose control of the air flow with honeycomb beds. Air flow across the material is lost, so the debris remains.
Here’s two video to help you out… first one is about 3 minutes the 2nd is a bit longer and more detailed.
I tossed mine and use a metal sheet with locating holes for jigs in it… Wipes down easily and doesn’t stink. You do have to raise the material for the best cut, so I have 5x20mm magnets for standoffs that stick to the bed.
In the end, you get to choose… choose wisely… 
Take care
