At this stage (barter) order book based pricing used primarily for speculation is vastly overrated. When you use XMR for barter what you get will eventually cancel out.
Later on, a elastic money supply, i.e. varieties of social credit based on trust as well as a trustless basis (xmr) will be necessary ... but it will hopefully support ALL people, NOT only the 1% parasites. (That's why I shilled OXEN BTW - credit could be an app there)
And, to put things in perspective, a -25% drop in price means nothing, compared to the effort put into the attack. Fiat drops -25% every so often (measured in real goods). Most people take that, because they rather carry on and not worry about the gun pointed toward their head. To use a racket like this as a unit of measurement amounts to moral insanity.