If I'm going to pay that amount of money, I want to get something else.
If I'm going to pay the same amount of money, I'd rather buy something different.
ーIf I'm going to pay that amount of money, I want to get something else.
「その金額を払うなら、何が別のものを買いたい。」
pay that amount of money で「その金額を払う」
get something else 「何か別のものを買う」
ーIf I'm going to pay the same amount of money, I'd rather buy something different.
「同じ金額を払うなら、何か別のものを買った方が良い。」
pay the same amount of money で「同じ金額を払う」
buy something different で「何か別のものを買う」
ご参考まで！
カナダ 
