Pi Zero single core, 512kB RAM, 700 MHz, plus shipping plus USB hub plus external LAN = 30 EUR
What?
Raspberry Pi Zero is sold for 5$ + 5$ shipping from thepihut.com and pimoroni.com (they limit order to 1pc).
Only cable needed is USB to micro USB cable that every Arduino user should have plenty of.
You ssh into Pi Zero over USB (OTG), and with internet connection sharing Pi Zero has internet access as well (for "sudo apt-get ..."). Of course Arduino SPI ethernet module does work as well ( I did that before I was able to get internet connection sharing right, SPI ethernet gives 4.7 Mbps, internet connection sharing 19Mbps and Ubuntu over same cable give 91Mbps):
Yesterday I installed "Raspberry" board into Arduino IDE following the corresponding chapter in Kolban's book:
Arduino Blink sample worked immediately:
Btw, Pi Zero is 1GHz, not 700MHZ. So "Raspberry" board for Arduino IDE makes "1GHz Arduino" available!
Hermann.