Hello,
I'm from Spain but I've lived about 3 years in America, and 17years in Spain. I also spent a few months in Holland (1.5months in Maastricht, 0.5 month in Amsterdam).
Gas is going to be way expensive, since in USA the gallons are dirt cheap. So if you have a 50L tank, expect to pay like 60euro+-.
Food tends to be more expensive, but the quality is 1000+ times better than American food, and if you want to buy cheaper food / fruits, during the weekends (Saturdays usually) they hold a Market where they sell different kinds of food, fruits, clothes, etc.
If you eat outside, it tends to be cheaper, but if you are not accustomed to Hollands food (which is not so good, sorry) it may be a little hard to eat outside at first. However, you can always find some Frites met mayo~
Living - It depends. When I looked for apartments in Maastricht, they were DIRT CHEAP. Like 300euro for 80sqm apartment, 500+ for nicer apartments fully furnished and in the center of the city.
However, Amsterdam is way more expensive. If you look for apartments within the center of the city, it may cost you 600 (cheaper I've seen for like 40sqm furnished), to 1000+ for a decent place.
Taxation is higher, but you usually get benefits such as the health system tends to be much cheaper.
Also, I've got to say that clothes tend to be slightly cheaper than in other countries that belong to Europe, but it cannot be compared to America, since the prices tend to be similar but in euros.
Example: Jeans - 30 dollar in USA, Jeans - 30 euro. So it may still be cheaper than in other European countries but still is more expensive than America.
It should cost you around 1000 euro a month (utilities paid - gas, light, water), if you have a car then addup 100-200-300 a month for gas even though I have to say they have
GREAT public transportation ... nothing similar to USA's.
Regarding food and clothing, you will probably spend about the same or a little more, just say if you spend 300 dollars or 500 dollars a month in food/clothing, then say 300~ euro.
So it could be anywhere from 1400 euro to 1700 euro a month in expenses. But I'm sure that as you spend more time there, you will find cheaper shops, tricks, tips... etc.
Good luck