You have several options to express the same thing:
1.) In Tokyo, if you bought these Ingredients I have been using for my breakfasts, it would be 3 times more expensive than that in the U.S..
2.) In Tokyo, if you bought these Ingredients i have been using for my breakfasts, it would cost three times more than that in the U.S.
3.) In Tokyo, my breakfast ingredients are 3 times more expensive than in the U.S./ In Tokyo, the food for my breakfast is 3 times more expensive than in the U.S.
4.) In Tokyo, my breakfast ingredients/ the food for my breakfast costs me 3 times more than in the U.S.
They are all fine and I think used equally frequently, so it is up to you which you prefer.