Beyond that, the constant relisting at lower prices may be good for the buyer, but that's really worthless. People who are producing high value items in any significant quantity are going to have the same effect on their inputs, so margins should be pretty stable (at the 18% crit rate for mod sellers like myself).
It is, however, annoying to those of us who list things at fair prices for long duration to have every "cheeze" seller able to relist and undercut at a moment's notice.
I dont see anything wrong with under cutting, as you say yourself it works better for the buyer since that drives the prices down. the "cheeze" sellers will come and go. Sellers will now have to set a reasonable price for their listings or another player will undercut them. I personally will under cut other sellers, but there is a line I wouldnt go below because that willl eat into my profit margins and would defeat the point of me crafting and selling..
e.g. I see people sell XXX item for 50k. I can sell said XXX item for 40k and still make a good profit. the people who set their price at 50k will have to bring it down to my level in order to get their items sold. simple really. If they complain about not being able to make a profit at the same price I'm selling mine and I'm getting a profit then they're not doing it right. They should consider looking at their costs and see how others are doing it instead of complaining other people are undercutting them.
I gather mostly my own materials and by the ones I can't do myself (this is more time consuming) but it keeps my costs low. If people buy in all their materials then their costs are gonna be alot higher than mine so they cant set the price as low as I can. I see crafting materials price set at x10 or x20 the price the items would be if you were to gather them youself and people are buying (I assume to craft with) as those prices havent dropped. If more people started to gather some of those items for themselves then the material sellers will not beable to demand those ridiculous prices
Its all about supply and demand. you'll see GTN prices drop until it hits a natural point. just the way all markets work. only reason profit was so good and prices high was because not as many sellers were around. and people got used to being able prices fix. that simply isnt gonna be the case for much longers as more crafter/sellers come through.
The only exception to those rules are the luck people who have extremely-rare or now unobtainable schematics like the WH purple crystal or the supreme inquis robe. They have the monopoly coz on one else can make them so they freely price fix.