Adding up numbers within a vector using a for-loop and an if-statement

I need to calculate the combined value of 4 houseprises within the vector Price (house1, house2, house3, house). The prices are in a database within the column current_price. How do I calculate the 4 prices, that are already combined in a vector, using a for-loop as well as an if-statement? The language is R. Kind regards.