Need help on expenses to beijing n Hong Kong.

Hi there, I'm a south indian traveller from Bangalore(Karnataka-india), planing my first trip to beijing and hongkong, as im travelling with my wife on a 10 days trip to explore both the places, but i have no idea on how much expenses i need for this trip, so i need your help......first of all, means of transportation around these places would be by metro or else by taxi. and secondly food, we love to explore chinese local food and of course our indian food which is available in some cities, and accommodation would be a 3 star hotel preferably, so on this type of travel preference how much would my 10 days trip costs for both of us? Need response as soon as possible.........thank you......