This reminds me of SWTOR in a way since you could always send crew mates to get stuff that would have been to time consuming compared to overall net worth. Now FFXIV gathering nodes are much more centralized and respawn at a faster rate but the system is still handy for those that need iron ore but don't feel like hoofing it out to La Noscea when they are waiting at the Garuda/Ifrit Node.

Also about the market being flooded maybe it was a balmung thing but all basic materials were always flooded. If anything even got below 20 pieces a price hike followed by a under cut flood would occur. So I doubt this will effect the economy anymore then people being there normal money grubbing selves. But sending out a retaining to gather might be counter intuitive if profit is your gain because if they are doing "chores" they might not be able to host AH spots for your stuff to sell.