I haven't been impressed with the mechanics suggested in Jewel of Yavin, anyone seen anything else that looks and feels better? or any suggestion how to do a commercial-encounter like that?

Moreover, player characters don't have strain-causing social talents, so I am leaning towards it being different then usual social-fighting, where its a race who loses more strain.

For context, this is for a middle arc in Ghost of Dathomir, the npc-mcguffin has been rescued but the shard is in position of a hutt and it about to be auctioned, players are using a local merchant to bid for them, against the npc-adversary's bidder, with assorted others (npcs might be lifted from Jewel of yavin).

I am not familiar with how they do the auction in JoY, but maybe you could run it like a race, using Cool or Negotiation as the relevant stat?

Are you doing it in person or on camera? Or through a chat system? Cause if it's in person then the auction can just be run in real time like normal. If it's in a chat system where people can't always post super quick then I would maybe suggest doing it in rounds. Everyone rolls Cool to determine order and then it goes around. Because in my experience there isn't a crazy amount of strategy in an auction. It's mostly just about who is willing to spend the most. Maybe some skullduggery or deception checks to hide that they're bidding or coercion to psyche out the competition.