I think if they bring regular trading back, they should also have a separate listing option in the personal shop that's separate from the main listings, where people can list an item, but it can't be outright bought. Instead people can offer other items they're willing to exchange for it, and the person who listed it can choose which offer they want.
This would stop people from doing what they did in the past to set up offer trades. In the past people would purposely list items at prices no one could afford, because they wanted specific offers instead, and listed what they wanted in exchange in the listing description.
This is related to trading because of course the only way to do offers was by trading. I think this would be a good fix for this problem so that there are less cases of items being set to misleading prices because the person doesn't actually want anyone to buy it.
I guess this could also technically replace regular trading if they use the same system I suggested for N-Meseta to item (or vice versa too), as the person listing can also do this by only accepting offers by certain people they want to trade with.