It's been so long since I've ever had to look at the ah board through the database. If you really look for it(make sure you have items in ah to spot this table easier) you won't miss it. I remember looking for it on my own and finding it easily. Sorry for not being any help there, yet I'm pretty sure it's easy to find seeing as to the database tables for shaiya explain themselves well.
I wouldn't suggest that as an approach for regulating the economy.
Not only will that be extremely tedious, but it will also make people mad. No one likes being controlled.
I say customize how much gold drops, if you have fortune coins make them all rare to keep people from using only those to get currency, make sure nothing can be sold for a huge amount of gold.
As well as offering gold sinks. Like ice cream merchants or a custom merchant selling items that people want to buy a lot.
That depends on what you have in your server though and how it's set up.
Just trying to suggest better ways to manage your time as of running things.
Gives you more time to focus on server issues(there always seems to be those) instead of wasting time looking through ah for over priced crap.
Yet if you truly wish to go this route I would suggest to make an sql query to delete any items within a certain ID or base price or however you wish to go about it whenever someone places the item for over the set amount you have in the query.
No I won't make this for you so don't ask that. If you don't know how to make a query I suggest extensively looking into this before even putting your server up.
Queries and understanding stored procedures save your life >.> like for real.