So, Let's say a 1/2" drill bit costs $5. Not a harbor freight one, but something decent, because you are going to be drilling steel. But you're not going to be using a nice drill press, you're going to use it on your back, on the driveway, under your truck to drill 30 holes to attach mounting brackets for a camper hold down system and super heavy duty hitch system.
Let's say you can drill 1.5 holes per drill bit, because of the awkard angles, difficulty in keeping the drill perpendicular to the workpiece, difficulty in applying adequate lubrication. heck, some holes might even take more than 1 drill bit per hole.
That was the situation I was in when I bought my first drill powered drill doctor. I have to say that it saved me money, not to mention time running to the the store to buy more drill bits. When I burnt one up, I could just sharpen it real quick and go back to work.
I don't really have the skills to sharpen a drill bit freehand, and the DD does a really nice job of sharpening the bit evenly and pefectly.
so I eventually upgraded to the motorized version. Not sure if its this same exact model, but I'm perfectly happy with it and next to a brand new bit, there is nothing like a freshly sharpened one.