Let's take character transfers, for instance. If I wanted to transfer all my characters to a server where my friends play (why would I want to move just one?) it would cost me a hefty sum. Add to that the fact that my wife plays wherever I play so we multiply that hefty sum by two. Imagine if I wanted to change my characters' races to those combinations that were previously unavailable come Cataclysm... how much would that add up to? It doesn't take an accountant to see that it could cost a small fortune.