"Also, I have another question - did the benefits from the Holocaust exceeded the costs?"

You're going to want to rephrase that question, as well as quantify what you mean. What are you counting as a benefit vs cost. Are you talking in numbers of human lives, are you talking in people who were no longer in the workforce and therefore possibly helped to boost the German economy or what specifically are you looking to get answered? Do you possibly mean that did the slave labor of the inmates offset the cost of running the camp?

I also think you're looking at a multifaceted question. You have to look at how the camps evolved over the years from a simple political prison system to hold enemies of the state similar to the GULAG in Russia but over the years they changed into the deathcamps we're now familiar with when think of things like Aushwitz. This question honestly could be turned into a PhD thesis if you really got into the details of individual camps and their economic impact either positive or negative on the budget of killing millions of people.

It's a dark subject but entirely fascinating.

You should definitely check out the United States Holocaust Memorial Museum website.

I found a record there showing one estimate used by the SS.

Best of luck in your search.

I think you may want to do some further research because you are throwing around quite a few things. Concentration camp does not equal death camp, death camp does not equal holocaust, transport does not equal trains, etc. There is also the issue of what time we are talking about. Logistics and the economy of the early concentration maps was very different from the late ones, you also got the differences between camps inside the Reich vs. the ones outside (not implying that those were similar either).