Almost all auction house tactics revolve around the undercut. It may be a single copper, a few silver or a few gold, or a freefall drop down to the price of materials. Regardless of the amount or the frequency, most undercuts share a common misconception: that you're controlling the market with your undercuts. You're not. Your competitor has the control. By undercutting, you've just let your competitor decide your price. You've let your competitor set a cap on your profits -- and more, you've agreed to accept even less with your undercut.
The inscription market sees more than its fair share of this, sometimes on a large scale. The low deposits encourage large number of postings, followed by even larger numbers of cancellations and repostings. Prices fall as each new poster accepts and trumps the previous poster's prices, until the market falls to the cost of materials and the walls go up. The final wall signals a complete loss of market control.
Once it's up, it no longer matters who built the wall. If it's your wall, you can't raise prices until the competition perched above you goes away. If it's not your wall, you can't raise prices on your auctions until someone breaks the wall. Stalemate, and out come the piña coladas.