It would be an Automatic Price adjustment button that automatically adjust all your retainer sales prices so it will be the cheapest in the market. Can only be used once per day. Resets on the same time server resets.
Also a button that allows us to send all the retainers back to work instead of clicking them one by one would be nice xD.
Why would I want to sell stuff for less than I could get selling it to an NPC and pay tax on it on top of that? I mean, if you want to risk it, I guess ....
I’m not sure how I would feel about the button that will adjust the prices I’m selling on the market, even if it’s reduced by one gill, but I definitely want a button to reassign all my retainers though!