It would be nice if the trade marketplace could operate with mesos. This would allow a more stable economy but also eliminate arbitrage opportunities. This is also a possible method to implement deflationary pressures on the meso, which would make Maple Royals more friendly to new players.
In the bottom right hand corner there is a green button called "trade". It was originally used by maple story as an NX marketplace where you could sell items for NX.
We don't have the marketplace so your suggestion isn't of much use unless there is a reason to implement it in the first place. If your suggestion was implemented Free Market would be obsolete along with physical stores and owls.