Yes there is. Tubez sell one. https://www.tubeszb.com/
I must be missing it. I see serial/usb and ethernet/Poe but no wifi. I do see a router that doesn’t list any network connectivity. Maybe that’s it.
I haven’t been to Microcenter in a long time, but I always remember them having lots of Insteon devices on display and in stock.
If there is a Microcenter in your area, you might have some luck finding what you need discounted.
Good luck.
I would have to disagree. By the nature of the frequencies they operate in, z-wave (~900MHz) would have a better range than zigbee (2.4GHz), whereas zigbee could have more bandwidth and speed.
This is, of course, all else are equal, and assuming one hub/coordinator with one end device. So YMMV.
But then, range becomes a non-issue if/when you have a good mesh. So here in this forum you don’t see a lot of discussion about range between the two.
Just want to point out. 
No wifi. The poe is what you want.
So run an underground ethernet cable to one of the buildings to connect to a coordinator (not sure what that is???). Looks like it’s no longer available though.
Actually no, I would run zigbee2mqtt on, say, a rpi in the shed and connect wifi between the pi and your ha instance.
I think I see, and just run separate Zigbee networks for the sheds and the house connected to HA via MQTT.
Precisely, in which case you don’t need the poe device, just a usb connected one.
Wired is always better, so run a cable if you can.
How far is the shed?
Straight line is about 75 or 80 feet. If I run an ethernet cable it’s about 200 feet.
Since it would cost around $300 US to dig trenches and run cables between the buildings I really had thought to use a couple of ZR’s on the outsides of the buildings to bridge the gap. Unless that presents some performance problem? I’ve always used Insteon so don’t know much about the pros and cons of Zigbee.
If you have good wifi connectivity you should be fine.
Other alternative - I think 25m or 80 ft would be difficult for zigbee. But do you possibly have a mains point between them? Say a garden light stand? You could use a mains powered zigbee device there to act as a router.
I have an outdoor receptacle (mains) on each building. Nothing in between except a few bushes. I thought Zigbee had a range of 100 meters. I’m sure that’s only theoretical but would have thought 25 meters would be fairly easy in open air environment.
Well you may not need any intervening router.