This might be a dumb question and maybe not the right forum, but there is a huge spread between MtGx and Coinbase. Any reason I couldn't transfer my BTC's from one to another to capitalize on that?
Yes! It's very hard to get your dollars in and out of Mt. Gox at the moment (this is not the case with Coinbase or Bitstamp). So what do you do once you've sold your coins at a higher price on Mt Gox?
When you see a higher price between in exchanges, there's usually some liquidity issue at play there.
No problem. Note that there are currency arbitrage opportunities in the Bitcoin market, but they're rarely as obvious or large as the one you see in the Mt. Gox market.
Also, note that the money transfer problem does not exist with Bitstamp or Coinbase, both of which are relatively easy to transfer money in and out of once you're verified.
When you see a higher price between in exchanges, there's usually some liquidity issue at play there.