MCM Electronics is selling a Sketchgarden/Nanode board for $10.00. Unfortunately the idea behind the sketchgarden firmware is long gone. The board is a older board, but it has a ATMEGA328 and a Ethernet port on it - the headers I believe are not Arduino R3 comparable, which means that some shield will not work with it, that is still ok.
In order to make the board useful, you have to flash the UNO bootloader on it, because it's a ATMEGA328 and not a ATMEGA328P the usual way to flash the new bootloader doesn't work.
I put together a short (17 min) video of how to flash it, it's not hard to do, but does require some extra steps.
As I said in the video, there isn't a lot of information about the board any more, and here is everything I found and what you may need if you want to flash the new bootloader.
Arduino as ISP
https://www.arduino.cc/en/Tutorial/ArduinoISP
Step 5 & 6 Bootload an Atmega328 by Andy Tallack
https://www.instructables.com/id/Bootload-an-ATmega328/step7/Bootload-the-ATmega328/
Wicked Device Tutorial (Sadly out of date)
http://shop.wickeddevice.com/2013/10/16/nanode-gatewayremote-sensing-tutorial-1/
JeeLabs Ethercard library info
http://jeelabs.org/pub/docs/ethercard/index.html
(This page suggests the CS pin is already PIN 8, the Github repository
says it's PIN 10, which maybe why I had to change it)
(I think this page is out of date as well)
CS pin is 8 for this board.
Ethercard Library
https://github.com/jcw/ethercard
