As far as the hand-made woods... labor intensive and requires special skill. They just aren't something that can be turned out in a factory.
As far as the metal REOs... Rob ain't gettin' rich on what he charges for them. I know a bit about what the aluminum costs and also have a really good idea about what his machine shop must charge (part of the business I work for does CNC work). I've also had a few things anodized... Not even the Chinese could make money cloning metal REOs while even half-heartedly attempting to give the appearance of similar quality.
Other materials like plastic... Personally, I think Old Goat was the greatest REO salesman of all time... Don't get that statement wrong: Old Goat made hundreds of plastic box feeders - lots and lots of people (including me) bought one or more of them. The Old Goat feeder was my introduction to feeders and was the device that got me hooked. I don't know how many other people I've read saying the same thing on ECF. Missy's wet box - kens - the army
tank - the kit madvapes had for a while... all of those cheap plastic feeders introduced people to feeders. And, none of those plastic feeders were built to last (not saying none survived - I am saying that none of them are built to survive). A lot of people bought REOs because they were hooked on feeders but needed one that was both durable and reliable. -- If a (or 'another' - depending on how you look at it) cheap plastic clone comes along, it will just introduce more people to feeders and make more people want a REO.
As to the other two feeders that get some attention - The Revolution2 and the Vmod... Well, the Revolution just isn't a very good product and the non-user-seviceable battery ensures the fact that owners of that device will eventually come looking for a REO... and the VMod... well, I try to be as generous as possible when discussing that device because it has some very vocal fanbois and a couple of very aggressive shills on ECF whom I've gotten a little sick of dealing with... but really, it's another one that has a strong likelihood of a minor mishap leaving its user unable to vape. That plastic insert just isn't going to last forever....
So, the end of the story is that: 1) Making a quality feeder ain't cheap even for China - 2) Anything less than REOs quality will sooner or later bring the user to REO.