Anyone have the Answer?

I am trying to learn how to measure my ac lines to see if they need
conditioning or Regeneration. 

Now it seems to me a person would want to know how bad an issue
they have before tossing out $3-7k for a machine to fix it.

I have asked this question on several forums and so far no one has ventured an answer.

Or are we as consumers supposed to just accept an issue exists and buy the product?