For full context, see here: https://www.docdroid.net/hK45eJm/img-20170916-0001-new.pdf
The sentence in question was taken from line 6-7: 現金収入が少ないため、費用をかけずに行わなければならないからである。
First, my attempt at translation: "Because the income was low, they didn't pay the costs while it was performed."
I just don't know how to translate a sentence which has two parts giving a cause. It seems like there are only causes, but no consequences xD
Second, 費用をかけずに. The only interpretation for かける which seemed to make sense in this context was number 3 on jisho: "3. to take (time, money); to expend (money, time, etc.)" http://jisho.org/search/kakeru But I feel rather insecure about it, so I wanted to ask you for confirmation.