If I buy with my own choices for the plane, TX, servos, etc, will I end up roughly the same price? I mean there are some parts that I don't need them yet, right? Or pretty much most of the above list is things that are required to fly a plane?

Some other things, is it better to buy a product that I can find spare parts locally or they are similar in some ways that I can use any parts to replace a broken one? I'm thinking specifically about the plane.
And what is trimming (as in setting up the plane when I want to use different plane with same radio)? Is it difficult to do or to learn?