Fixed exchange rate multiplication

In small demo you get this:
```
At MtGox I can get 946.00 BTC for my 10.00 USD (that's 94.60 USD/BTC)
```

You should get this:
```
At MtGox I can get 0.11 BTC for my 10.00 USD (that's 9400 USD/BTC)
```