No matter how you work, you will pay fees, hidden in the conversion rate. Banks & businesses have make money somehow... You should just try to minimize this. Currently, on the middle market rates, US$ is worth slightly less than the CA$ (1USD=0.99CAD), so a good exchange rate would be around 2% higher 1USD= 0.97CAD, meaning it would cost you 103$US to buy 100$CA. That’s what I get (the other way around) when I exchange money at my favourite place here. It also looks like people are able to get that at casinos in Niagara as well.
Credit cards & bank fees are very variable, so you’d need to check with yours. I know some American credit cards will charge an extra 3% fee on top of their exchange rate for “foreign transactions”, but not all of them do (mine doesn’t, I just pay around 2.5% over the middle rate, still quite good). If I take money out of an ATM, the exchange rate is similar, but I will also get hit with a service fee. I have no idea how it work if you use your Credit Card in “Debit mode”, as this is very unpopular here (was not even available until last year, we have another debit system).
As I travel frequently out of country, I found the best strategy to be:
- get paper money at the exchange office (as much as I think we’ll need + some insurance, or as much as I feel comfortable carrying!)
- pay mostly with my credit card for large transactions, and use cash where needed
- get paper money at the ATM if I run out!
Since you are doing a short trip, I’d just exchange paper money where you can get the above mentioned rate or close to it (and remember, when you’re talking small amounts, if you pay an extra 1-2%, it’s only a few dollars, don’t stress it!), and pay with a credit card if your provider does not add an extra foreign fee.