We are talking about major exchanges and as someone said , the price doesnt get high by the exchange, if the price starts to raise, and lets say only btc-e has the old price, the people will inmmediately get money into btc-e to buy cheap coins and then the price will spike too, and thats where from the exchange will pay to the people who wants to withdraw.
and btc-e, bitstamp, coinbase are not running by two persons, see the buy orders from btc-e, they have 10 millions dollars on it, do you believe they cant afford more people?