I think the point is that the trade goods have to be valued more than the cash price for a deal to be considered since inorder to liquidate the "trade goods" it will take time and effort before "cash" is seen. The value is subject to the buyer and sellers agreement and I don't think you can inflate them for the deal.
I guess if the goal is to sell, that's a good point.
How many individuals are doing that, though?
I think the point is that the OP is accusing sellers of being shady for offering a lower price for cash... which is odd, because a lot of sales (cars, gas, houses) are just that way.
Not at all.
While I compared it to a car sales, I do consider it shady for a dealership to offer more trade and at the same time artificially inflate the sales price.
But I'm not seeing gun dealers do this. It's private, individual sales primarily.
The point all along, as it pertains guns, has been why two values for a cash deal vs a trade deal in a private, non-dealer sale?
Marketing, resale, and just because have all been discussed.