So why do manufacturers try to make money out of...water?
Everybody who tries to simplify things forget about another very important and expensive ingredient: the labor and people's knowledge multiplied by time spent on producing these goods.
It seems like labor isn’t worth anything and things should be sold at cost and that's what is considered to be the "fair business". But sugar paste is not only sugar, water and lemon juice. Sugar paste is, first of all, laboratory researched, with work of chemists to develop the perfect formula. It takes a lot of work to learn the process and ability to distinguish monosaccharide sucrose from fructose, to understand the fermentative hydrolyze specifics, and it takes a lot of hours to find the optimal proportion of the ingredients.
Sum up knowledge of marketing and ability to organize an efficient and honest business, rent, salary, expensive equipment, logistics and on top of that, as much as your conscience will allow you to, add a bit of interest margin with a tiny bit of profit.