The world is immeasurably big and, as such, things tend to change from one country to another. One of the things that changes the most is the cost of living between countries, which expert travelers keep in mind throughout their travels. A five-star hotel in India may cost you less than a cheap motel in France. Knowing the cost of living in different countries should help guide your budget and lifestyle during your stay.
So a general rule of thumb would be to really treat yourself to a luxury vacation where things are cheap and stick to a tighter budget at the more expensive destinations.