As the author of the post, I wanted to subtly return to the topic. Well, let's take a look at the following situation ...
A client calls me and says that he needs to do an installation, and I know him by sight. Initial inspection, measurements and I already know theoretically how much material I need. Theoretically, because people simply make things up - the husband wants otherwise and the wife has her opinion. The customer buys the material and I only go with my tools which is quite normal

I count points like this:
Tin - Nest
Can - Switch - Lighting point
Leaving each subsequent can.
Now there is a problem of what to do with, for example, a 19-meter-long point. Well, I figured it out like this:
I count the point up to 5 meters of the cable, and for each started, I add 5 zlotys.
So from 19 meters I subtract 5 meters and multiply the result by PLN 5.
My price for a point up to 5 meters is PLN 35. I don't know if it's a lot or a little. Help me figure it out because the topic is really problematic, and since I live in a small village, there is no one to talk to on this issue.