Apparently Craigslist isn't big in Japan. I searched Craigslist-Tokyo on 'sony' and 'samsung'. Surely a lot of that gear gets sold used. I got only one hit each, the same ad, from a US firm selling karaoke software.
Then I brought up all of Craigslist-Tokyo Farm&Garden. Over the past several weeks there are only five listings, all North Americans advertising stuff to the Japanese, plus one American living in Japan offering American-style Halloween pumpkins. "If you don't have a car, we'd be happy to meet you at Numata station with a selection of pumpkins ".
And I didn't find any Yanmars on Vietnam Craigslist either.
Two 'sony' listings appeared, which I think verifies that I'm searching correctly.
I think you need to find some regional Equipment Trader - type websites.