From a knot free 1 X 12 X 16, I was getting 110 top bars. With a micro kerf blade, I get 120, an increase of 9%. The math works out the same for any frame parts, I get 8 to 9 percent more of whatever I am cutting. Just changing from a 90 mil blade to a 60 will improve yield enough to justify the change. 6.5 inch 60 mil Freud blades can be purchased for $20. Also, please note that it was not an 18 mil difference. I was using a 90 mil blade and went down to a 42 mil which means 48 mils gain on each piece cut.
My blades of choice now are Freud LU86R010 for general purpose cutting, Freud Diablo D0641X thin kerf for cutting down 2 X 6 into smaller stock, and the 42 mil micro kerf blade for machining frame parts. I have a Freud 206 dado, a Freud 24 tooth ripping blade, a Freud 60 tooth finish blade, and a Freud 80 tooth plywood and melamine blade. I use them, but not nearly as much as the first three. Are there better blades? I could point out a few that are as good as or perhaps even a tad better under some conditions, but for my purposes these blades do all I ask of them.
You are correct that the 42 mil blade will get dull sooner and has a shorter lifespan. It can be re-tipped up to 10 times and sharpened up to 10 times on each set of tips. Given that I have used it to cut 1000 frames so far and no sign it is getting dull yet, it will probably last longer than I will.
I am cleaning up old equipment and preparing swarm traps for next spring. Today was clean up the greenhouse day so I can start seed in January. Tomorrow I plan on assembling some more square deep boxes and perhaps painting some of them. The bees are enduring a rainy windy cool night. They have enough honey to make it to spring.