I fully support concern towards authors of the books and the cost involved in publishing such books.
Their books are shared till now free of cost, but, in capitalism system, every deed somewhere related to the greed
Greed of this website
, at present, may be that they are crowned by the public around the globe as the highest source of information.
At present, donation system is present in the wikipedia, but, I'm not sure whether it can fulfil their ulterior objective as business house.