I dont see so as well, the only improvement would be something similar to EVE contract sales, where you post x items selling at x a piece, and people can buy 1 or all of them at set price. Undercutting by a gil or two, is almost caused because of the fact that partial stocks cannot be soldm so here we go. If Im levelling a crafter, or for whatever purpose, I only need 10 this or that. I'll usually go down the list and buy maybe 12 because its totally closer to the amount I need. Outside of the system in place? I think its fine, 1 gil, etc whatever. Im sure theres disagreeance, but you know, supply and demand have a very big impact on value. As they should, and if anyone dumping their supply for 1 gil less, is any less of an indication of that. well I dont know. Yeah. I do this too, but im not much of a mb supplier, Im more of a combatant, thats just trying to get the stuff out of inventory so i can make the money as fast as possible. Some are like me, others are more professional about their sales and what prices they claim are "good quality' but most likely a combatant ran through a map getting through a fate and 2 shot this wildebeast, so yeah that really held little value over what some might potentially feel is worth.
TL

R - basically the only thing for suppliers to enhance the current system, is a buy by need listing, limited of course by whatever means, but thats all I see is necessary. Not everyone needs your 99 lumbers at said price. Of course. this should be OPTIONAL and limited either by retainers present(say 1-3 supply contracts per retainer) but even then it alleviates some issues. Its never going to 100% work in your favor, unless you spend all your time watching the numbers. Which you could, if you wanted to, but thats also your choice at this point.