The price of the Tokyo Hilton is not expensive to me given the upgrade and price. You will spend lots more for your upgraded room at any other western style hotel. If you want cheap there is a McD, tonkatsu and AM/PM store in the building basement adjacent to the Century Hyatt (two minutes tops from Hilton). Also no need to walk to Shinjuku station. Free shuttle or take the subway line behind the Hilton to Shinjuku station. Marounouchi (think thats correct) line.