Yes, you are right. That doesn't make a real big difference. To compile from the source on RPi 1 would take several hours. It's better to use some kind of cross compiling. On a RPi 2 or 3 you also could disable the HDMI port and some other unused parts such as WiFi or Bluetooth, that would also reduce the power consumption.
On 17.10.2016 00:32, Tristan wrote:
I believe the 2 and 3 are the same price as the 1 though. At any rate, you should probably compile the latest Tor from source if you can't use the official repository.