So after reading most of the replies here, i am likely to believe that those who are a hard no on this type of market structure have absolutely no experience with similar, yet better designed marketing systems. Put simply the FF14 marketing system is nearly identical to EvE online's, if you hit the developer in the head with a monkey wrench and he suffered a concussion.
Things that are similar:
Regional Taxing
List price sorting.
Limited sell orders
Things that are different
all regions are visible
entire listings must be purchased
no buy orders
Now it is very well possible that SE purposefully injured their market developer so as to be just different enough to avoid a copyright lawsuit. In which case legal is the reason we cant have nice things. That is just pure speculation though.
Lets outline exactly the features of the ideal system would be.
Instead of each item listing being sorted by price AND seller AND stack.
each listing should be sorted solely by a total of listings at a sorted price.
so for example, instead of seeing 4 listings of hemp cloth for 30 gil for 4 stacks of 99 by the same person, i would only see 1 listing for 30 gil that has 396 units of cloth.
lets expand this scenario to multiple people selling it at 30 gil per unit but different stack amounts.
again i would see 1 listing for hemp cloth at 30 gil per unit but now i would see say a total of a couple thousand units.
then ofcourse i would see few listings at ridiculous prices of say a few thousand gil per unit. we have all seen that one guy who has to sell his copper ore for 999 hundred million.
So the question comes in ok, so who get paid when product is bought? I believe it would work like this:
the youngest sell orders get filled first. if you notice you are getting undercut or find yourself in a saturated market, lower your price and undercut more. Notice how this competition is exactly the same as the current one.
Now for the bad news... the market in its current state is largely exclusively for those leveling their crafting. nearly everything that can be made by a crafter that is beneficial to someone PVE is also available from a NPC vendor or quest/leve reward often times is better than what you could get from a crafter. leaving really only one exception the entry level endgame ilvl 380 gear. everything else is just glamour or used to level crafting. so ultimately the market itself is largely niche and this wall of text is mostly irrelevant. So until the demand for the end products expands farther outside the realm of crafters there really is no need to change the current system outside of convenience