There's a million ways to skin this cat, but perhaps limiting the number of posts of the same item by the same person at once would create a more diverse economy by allowing other players goods to be seen, and also make it easier for me to find linen cloth, instead of one undercutter having the first 9 pages of the auction house "linen cloth" search by posting one linen *bolt* for 12 silver XD It's practically spam.
Or, one could increase the minimum stack size for certain trade goods.
Or, one could limit the overall number of auctions one can post at once (if it's not already, then lower it?)
Or, and I don't know if you guys can do this, give the auction house search feature a NOT section to filter out items that partially share a name (for some reason the auctioneer addon does not function for me in this way, but auctioneer does not solve the economic or diversification benefits that my first suggestion would provide).
I think the first idea is the best; nobody should be able to take up more than a page worth of sales of a specific item at a time. And if you're hoarding that much because that's your product that you choose to sell, then farm in smaller time frames; only farm for 10 minutes, go post your garbage, and while you're out farming, they will sell. If they don't sell, then you're production is overwhelming your sales ability, and that's no excuse to use the auction house to hold your stuff. That's what your bank account is for.
Ok, argument complete XD Lot's of solutions to choose from.