I got it shortly after I heard they were discontinued, so there was still some stock floating around. I think it might have been through Dick Smith/Kogan at the time?

If you're willing to go down the Amazon route, I think Echo Dot's have an aux out? They had a device called the Echo Input as well which was like and Echo Dot without the speaker, doesn't seem available anywhere though. I would probably only try this if I could be sure I could disable the microphone and smart speaker functions.