Could you help me to understand how can I write this sentence, please?
As much more money people have, as much more they want, or
The much money people have, the more they want, or
The more money people have, the more they want, or
The most money people have, the most they want ?
When you want to express that one thing leads to another, you use the ..., the ... with two comparatives. The comparative here is more, so you use
The more money people have, the more they want.
If you use the followed by a superlative, it indicates the maximum that can be reached, as in
The best they could hope for, was to save their lives.
Much in your example is the indicative, and "the much" is ungrammatical, so no, you cannot use that (as far as I know) in any correct way.
"As much more" is ungrammatical, you are confusing then "as + indicative" as in:
As much money as they have, they always want more.
With the the, the construction that you are trying to form.
"Much more" is a strange construction in itself; you use "much" to indicate that we are not talking about simply more of something, but more than that: it is "a lot more".
This simply does not work in the construction with the/the.
