First off, $400-$500 is enough money to do way more than just wash the car. That will get you the entire paint correction kit along with everything you need to maintain your paint. Most of that stuff is a one time purchase. Or, you won't need to replace anything soon if you use it correctly. Most novices waste more product than necessary.
I want you to check out my
wash series, as I don't think that you have seen this series. There may be things that you are willing to revise that are not expensive at all (like 2 wash mitts for the car and none for the wheels and tires). You can use some other stuff for those, unless they are painted and clear coated. Then, let me see your process again.