Yes, I think online auctions on eBay and other sites will always be a popular online activity.
People like a good deal on items, or want to sell their stuff for higher than retail price like how some people sold their Nintendo Switch for hundreds of dollars more than the Switch's retail prices...
No, I have not re-sold my old gaming pc, or gaming parts on eBay.
But, I think if you upgrade your video card often to play newer games in 4K, it could be a good idea to sell your older video card to get some of your money back rather than re-using the video card on a older regular desktop...
I think in some countries like China, 1 US dollars is worth a few Chinese dollars or cents, so the factory may end up making money by selling it for a US Dollar, and paying for the cheapest shipping which takes months to arrive by ships, and trains instead of a truck or airplane which is usually...
All details on my ebay page, plenty to get for the cheap price. Let anyone looking for a 3DS know please.
Leading the charge in something new, Nintendo of America has open their own Ebay store to sell new and factory-refurbished systems, games, and accessories directly to you the gamers.
Check out their stock here: