An oversaturated market will happen very quickly in FFXIV with the crafting system. BoE would do a little to help that situation. If it where to be done the way I'd like to see it would be you do a synth with a normal quality item and some special ingredient. Make the special ingredient fairly common and give the synth base 30% to 50% fail rate and higher when the crafter's skill is two low. The failed synths will remove a lot of the garbage gear from the economy allowing crafters an oprotunity to create more items. The successfull synths will then be much more expensive as the result of higher costs as they should be anyway.
Being able to vendor the excess for a reasonable price would also help with the oversaturation.
PLD/BLM/PUP 99, RDM 86, SMN 90, WAR/NIN/WHM/BRD 50, DNC/SCH/MNK 37 THF 29, BST 16, RNG 12, DRG 8, DRK/SAM 7, COR 5, BLU 1
also, if something goes wrong, pup is the easiest job to blame. You can keep one around just for that reason. If there's a mijin gakure and everyone dies, just blame the pup, he's used to it.
Creed +2 5/5, Geotia +2 5/5, Pantin +2 3/5