You are buying the best of the best in brand names my friend you can get just as good much cheaper. Sorry but paying 140 bucks to punch a hole in leather is just dumb when there are plenty of good alternatives so I guess my answer is no they don't perform better that cheaper alternatives. I will say i have never used a Blanchard but i will also say i have never needed one my cheaper ones are fine. I use craft tool pro series diamond chisels and they work well for what they do.
if your making bags totes and boxes you will need punches. The punches are for cutting inside corners, Card slot ends, strap slots and such. As well you will need a stitching clam or all that hand sewing will be really sucky to do. You might also get rivets or snaps and a setter.
Strap cutting tool is also helpful.