Im having the same problem on my server atm. Glyphs going for 70 b/o, and the good ones at 30g+ avg for weeks on end.
A new guy comes along and posts 15g fallback, 5g threshold. one of every glyph. Its crushed the glyph market on my server. He only posts 1-2x per day from my experience too.
Tell me about how the glyph wall works. The only problem I have is that Im sitting on ~250 stacks of herbs and just 200IoTS. I do have a stock of 12-20 of each glyph in the inventory now. I dont know how long I can keep a wall up.
I have no farmers hooked up. Theres only one on the server and he sells on the Ah. I've had no luck contacting him. Herb prices are very high 20+ mostly. I just dont know what kind of amount of ink I may be needing to keep a wall up.
A wall is fascinating because no profession other than Inscription is capable of forming one. This AH strategy occurs only in glyphs - a high-volume, intensely competitive market.
The purpose of a wall is to drive out one's competitors - either by forcing them to run out of supplies, boring them, or making them feel that lower profits are not worth the labor that goes into crafting and posting glyphs. As a long-term strategy it is fairly effective and can drive out competition as well as discourage new scribes from entering the market.
To form a wall, a "mason" simply needs to set his QA3 to post only at a set max amount and under - for example, if Glyph of Blahblah is at 30g he will only post his at 15g. If Glyph of Blahblah is at 14g19s he will post at 14g15s and so on, with a minimum threshold at the bottom.
So what can you do?
Our friendly neighborhood anon is in a tight spot. He's got a small stock and no farmers hooked up to supply him with cheap herbs. He fits perfectly into the waller's target range.
Every cloud has a silver lining though! 15g a glyph is still a good price. It sure beats a 5g roof, and even with herbs at 20g a stack you can turn a profit. Even better, I can immediately spot some glaring holes in his competitor's wall.
1) He only posts twice a day. He is not a camper. Phew! This makes it a zillion times easier. It won't eliminate the wall, but the first thing you can do is add his characters to your friends list and undercut as soon as he logs off. (If you're not using Quick Auctions 3, set it up ASAP!) Since you have a large stock of glyphs, only post 1-2 at a time so you can keep more in your bags to undercut without wasting time canceling. If you can keep your glyphs under his he will notice his profits drop even further since you will be getting all his sales, and it might force him to let up a bit. At the very least it'll keep your profit margin high and indicate to him that you're serious.
2) What's even better about his posting schedule is that it makes it very easy for you to price reset! Do you know which glyphs are the most popular on your server? (You should. :P ) After he posts, buy out all of the popular glyphs and simply relist them at a higher threshold. You can make all your money back easily and increase profits for the rest of the day until he relogs to reinstate his wall. In addition, it saves you time and money crafting those glyphs - he's doing all the work for you, no farming or herbs required. This is a fantastic strategy for scribes hurting for supplies.
Some examples of reselling glyphs can be found here:
Just My Two Copper: Tailoring and Inscription Goblins Misconceptions
Buying up low priced glyphs and relisting.
I hope some of this is helpful to you. There's even more information about walls in the JMTC forums (check out the Inscription board).