Geez... Good question and I don't really have a good answer.
I bought a bottle at the start of summer in 2017 and didn't buy more until the start of 2018.... So I got a season out of a bottle if that gives you an idea. Of course, I have a convertible, so that cuts down a bit (don't have to do the roof). A bottle is around $10 and I buy from Autogeek or Amazon. The key is to use several microfiber towels. I use three... One for the hood and deck and one for each side.
This also covers "rinseless", but I have never used that.
All sorts of YouTube videos with some searching.