Shade, a film, and a new window are three different projects. This site refers window replacement. It does not sell film.
Name the wall
A north window and a west window are not the same problem. If the room you cannot sit in after 3 p.m. faces west, say that. Ask the contractor how the quoted glass treats solar heat on that orientation. The answer should point at the label, not at a brand adjective.
The frame still matters
One pane of glass in an aluminum frame is a weak start. Two panes with a coating can change how the room feels. Whether it changes a bill by any particular amount is not something this site will guess. The rest of the house, the shade, and how you cool it all sit outside the window quote.
Inland is not the coast
El Cajon, Santee, Lakeside, and Escondido get a harder afternoon than La Jolla. A coating chosen for a mild coastal room can be the wrong conversation inland, and the reverse is also true. Ask for the unit that matches the wall you have.