The budget is split over various factors and your trip cost depend upon the same , some of the main factors are :-
1.) flight tickets price 2.) your hotel preference:- 3,4 or 5 stars or hostels 3.) if you get a trip planned from someone else you might pay extra so plan your trip yourself 4.) public tranposrtation or cabs in the host city 5.) and food , you should not go for cheap food as if you get baad food you may gey sick and a sick traveller is not a happy traveller ,your trip will get spoiled ,so try street food but do not go for only eating street food