Price variablility

[kenstu22]

I'm not sure I understand why the price of BTC varies so much (between $104 and $115 on the five exchanges besides Gox). I understand now why it is so high ($118) at Gox, but can't explain the other differences.

[C10H15N]

The exchanges are still in arbitrage equilibrium as long as the cost of moving your common trade instrument between exchanges exceeds the BTC spread.

[marcovaldo]

In some exchanges like mt.gox it is not possible to cash out usd, so everyone is buying btc.
In some exchanges like btc.e it is very hard to fund the account, and the fees are high, so the price is low.
In some exchanges like bitstamp it is very easy to fund and withdraw from the account, so the price is average and fair.