I can try and answer some of your questions, but to be honest, I can not account for a specific card or transaction you had. Warning for all, a bit long winded.
First, very basic, any transaction has a cost, so any conversion will be more than the interbank exchange rate (outside of variation in the actual exchange rate throughout the day), the question in the end is how much is that cost.
Second, forget terms like "fees", "rates", "exchange", "commision", etc. They are all costs. The basic calculation is: for X amount of (euro, Canadian dollars, whatever); how many Dollars did it cost.
Third: Costs can be broken down into two types "per transaction" meaning a flat fee per transaction, and a "percent of transation", usually an exchange or transaction rate.
Finally, these costs can occur or are imposed by:
- The merchant, vendor, or owner of the terminal you make the transaction at
- The Network that handles the transaction
- Your bank or credit card company
Given all of the above, and all of the possible combinations, it truly can be very confusing, but here are some possibilities to consider.
Merchant/Vendor fees: Generally, in Europe, the merchant does not charge a fee for using a credit card or even a fee at an ATM. You very well may run into a tactic known as Dynamic Currency Conversion (DCC) where instead of the merchant or ATM completing the transaction in the local currency, they kindly offer to do the transaction in your currency (Dollars) usually at a rate of their choosing (maybe $1.24 per euro vs the current $1.13, about a 10% cost) Other places it might be a $3 fee for using an ATM. The more you decline these costs, the better you are.
Network Costs: These tend to be fairly consistent. For the Cirrus, Plus, Maestro...all charge a percent of costs that total about 1%
Your Bank/CC: They can actually be the worst, or at least the hardest to avoid without switching, the most common is a 3% cost on foreign transactions, but it may also be just a flat cost for doing a transaction, or a monthly/yearly fee for using the card.
All that said, you need to break out your costs into each category and evaluate. Some examples from my travels:
When I use my ATM card, I always decline any DCC, I know I will have a cost of about 1% over interbank rate chrged by the network, and my bank cherges me nothing, except maybe a monthly fee if I go over so many transactions.
I used to have a credit card that charged a 3% foriegn transaction fee, but not now, so total cost is just over 1%, plus any interest if I fail to pay off the balance.
Exchanging money in the US at a bank before I go....best I found is Wells Fargo, no flat fee, but the exchange cost is about 5% over interbank rate.
Exchanging money at an exchange bureau, sometimes a flat fee, sometimes a "commision" noted as a percent of the transaction, and always a percent cost for conversion (exchange rate) typically totaling about 10% over interbank rate. If you really want to waste money, use a credit card with a 3% fee and do it as a cash advance at an exchange bureau.
In the end, understand what your bank/card charges for costs, be aware of DCC and other costs by a vendor, and eliminate as many variables as possible to get the lowest cost.
