Totally agree with this, when out of my home country, I used a foreign transaction fee free card so it always works out best for me with local currency.Here's the story. If they offer you to pay in your home country, the only time you should do it is if your credit card charges more than a 3% foreign transaction fee. When you select to pay in your home currency, you will have to sign 2 cc slips. One of them is for the currency conversion and it says in small print on this slip that they are charging a 3% fee.
The first time it was offered to me, I asked the SA if there was any difference or fee...I was told "no". Then I read the little slip and was livid.
If your card charges more than 3%, it would be worth it. If not, stick to local currency..
Happy shopping!