Why are prices so different between exchanges?

[JorgeStolfi]

Just moments ago, 1 BTC was 900 USD on Mt Gox, 850 USD on Btc-e. 

Why is there such a large price difference between exchanges? What prevents people from making a profit by buying bitcoins on BTC-e and selling them on Mt Gox, until the prices match?  Is it the difficulty of moving dollars between the two countries?

[MatTheCat]

Just moments ago, 1 BTC was 900 USD on Mt Gox, 850 USD on Btc-e. 

Why is there such a large price difference between exchanges? What prevents people from making a profit by buying bitcoins on BTC-e and selling them on Mt Gox, until the prices match?  Is it the difficulty of moving dollars between the two countries?

A premium on MtGox cos that was thee original btc exchange, but these days, it is very difficult to get currencies out and back into foreign bank accounts.

BTC-E, I have used for swapping Btc into Alt-coins only. I thought about getting some Euros into my account on there to take advantage of the arbitrage between it and Bitstamp....but As I was about to do so I noticed the "Transactions will be accredited to your account in around 7-10 days" message....erm, no thanks.

[udet4food]

Just moments ago, 1 BTC was 900 USD on Mt Gox, 850 USD on Btc-e. 

Why is there such a large price difference between exchanges? What prevents people from making a profit by buying bitcoins on BTC-e and selling them on Mt Gox, until the prices match?  Is it the difficulty of moving dollars between the two countries?

Arbitrage is very slow process, I waiting for BTC-e deposit myselves and support not responding, not fun at all.

[hieroglyph]

As many have posted on the forum it can be very tricky to get the arbitrage trades in and make a profit.  And from what I've read here it's not getting any easier.  I'm gonna try and make a trade soon so I can better understand what everyone is talking about and maybe even make a little coin.