[plsoucy]

They really don't (unless you compare them to PayPal, I guess). They take 2-3% of commission to convert your funds, which would mean that they charge you $200-$300 for currency exchange on a $10,000 payment.

If you want to convert your funds at a "Big" Canadian bank, please do so at Tangerine, which has the best rate I found (they take 1.45%) - otherwise, there are plenty of other suggestions in this thread that could help. The best rate will most certainly be with Interactive Brokers (max(0.01%, $2.50)), but the account set up is a bit tedious and they have a few restrictions.

[refurb]

Of course you have to comparison shop, I have no doubt some of the big banks will take advantage of the uninformed.

That said, it's much easier to convert USD to CAD in Canada, then CAD to USD in the US. I had an account at a small regional bank and if you were converting less than $100 of CAD, you'd be lucky if you got 2/3rds of the actual exchange rate.