At the moment a lot of players are madly levelling up tradeskills.
For example, and enchanter I know has 520 skill, trying to get to 525. The mats are costing him about 500g per point, and he can only sell the scroll for 40g. This is only sustainable while tradeskills are being levelled.
One day soon, there will be less toons levelling enchanting. As I didn't pay much attention during the start of Wrath, I dont know how long this rush of tradeskill levelling phase will last. What I do know is that in the long term, either mats will come down, or the cost of the scrolls will go up; probably both.
I have always been a contrarian investor - sell during panic buys, and buy during panic sells. On average this has worked well. I advocated hanging onto snowfall ink when the price fell to a few gold each. On my server, snowfall ink is now selling for 13g.
I don't know what the long term prices of items will be, but it does seem that some items are currently oversold, and that oversupply will dry up.
It may be time to go shopping.