I heard exporting large volumes of a good will lower prices over time. I think I've seen prices change, but haven't paid much attention to them. My city exports a lot of TVs and I was wondering how low the price can go.
The global market will be server wide; with prices coming to some sort of equilibrium (I believe there will still be price caps and floors). As such I expect the price of TVs to drop a bit -- however they are used in the construction of the Arcology great work so maybe it won't be that bad. But TVs won't be the money making machine that it is now...
 currently disabled.  their existence is covered in SimCity preview articles from ~December but these, of course, are short on details and long on fluff.
SimCity will have a global market that sets shared prices for commodities. How malleable or open to manipulation or catastrophe will the world market be? Can the price of oil crash and create a shortage?
Librande: Yes and no. We didn’t want to make an EVE system or a World of Warcraft auction system where the players have control of the prices in that way. Those economies tend to spiral out of control over time, since money is an infinite resource. You just start a new city and start making new money. The way the global market is set up, we have bounds on the high and low prices. We won’t allow the price to go outside those bounds. There’s a little bit of price-fixing on that side to keep the game playable. Then we tuned a lot of the commodities so if the price maxes out, you probably don’t want to be working with those resources.
Here’s a specific example: I’m drilling oil out of the ground and converting it into fuel. The more fuel I sell, it’s going to start to lower the price on the global market. But my single contribution to that lowering is a fraction of a percent. If everybody on the server starts dumping fuel and nobody’s selling oil, then you’ll start to see the price of fuel drop down and the price of oil rises up. The idea is that encourages people to say, “Well, I’ll just start selling the oil and get out of fuel now.” Then that causes the opposite thing to happen. From a design point of view, the idea is that we didn’t just want someone to write a guide, like, “Here’s the FAQ. You should always make this and sell that.” If anybody thinks they’ve found a flaw like that in the game and says, “You should do this!” and everyone starts following them, that actually changes the whole price structure. That invalidates that technique while something gets boosted on the other end.