JP and Michael both are wise in the way of bees as is Jim. I myself can agree that even though feeding may not be a desirable option, it is sometimes necessary. This comes from personal experience. I bought 10 colonies. I figured a similar thought, that they could build on their own accord and do fine. Problem was, I was starting them out foundationless which I find to be more natural. At that time of receiving the bees the nectar flow was minimal and after a few weeks of them building their comb I began to notice dead bees. I looked in the colonies and saw they were stuffing themselves in their comb. The comb was dry and it was a matter of time before they would starve. The nectar flow was not there. The next flow wouldn't start for a week or 2. I quickly made some "ghetto" feeders, filled them with sugar water and the colonies quickly made full recovery and I only lost 1 colony. The thing to remember is that it takes about 10 pounds of nectar to make one pound of wax which is a lot of work for the bees to accomplish. I now have 16 thriving colonies and check their stores regularly to see if feeding them may become needed. Right now blackberry and white clover nectar is flowing so no need to feed.
As a "cheap" note, the "ghetto" feeders were clean 20oz soda bottles with pin holes in the bottom, filled with sugar water and suspended near their entrance to reduce distant flights and help increase in production during the time of building their comb. Worked great and was a quick fix.