When I was abroad, a few merchants offered a "percentage discount" if paid in Euro as opposed to credit card. So, if they are inexpensive meals, it may be worth it to you to pay in currency. Make sure you get a receipt for everything you buy - even if paid in Euro just to remind yourself what you bought or ate to keep track of your monies. I wrote on the back of the receipt a general description of what I bought - meal or trinket, etc. Some smaller merchants may not itemize for trinkets. Restaurants did, but the itemization may not reflect on your copy of the receipt (just a total.)
I strongly encourage your bringing a Visa (MasterCard) with you, despite the higher fees, just in case the hotel(s) insist they do not take Discover or Amex. If that is the case (I would not chance it with bringing only Discover or Amex), you may have to just "chalk up the fees" so to speak instead of ruining your long-awaited vacation. If this is mostly to pay for your hotel(s), then it may be worth bringing the "safety net" of the more accepted credit cards - Visa and MasterCard. (I thought you are bringing larger amounts of country currencies to pay for most meals/wine/cafe, trains, admission fees, etc.; hence the "money belt vs. neck wallet vs. fanny pack" decision.)
With credit card companies upping their perks, etc, more and more people are using credit cards for just about anything - even $2, so they can get the "rewards" points. It would be beneficial to those who pay off their balance each month.
Visa/MasterCard does not decline a $1 charge. It may be suspect only IF a person stole a card number and was "trying to see if the card worked;" so the thieves tease it by charging a very small amount. Merchants and restaurants set their own limits about the "$10 minimum" purchases. It may be too because of the fees, etc, Visa/MasterCard impose upon the merchants to use the credit machine. So a person "charging a dollar or two" is not beneficial to the merchant - more of an expensive hassle.
Maybe these articles can give you some insight.