If cost is a major concern, 9mm is cheaper over the long haul.
Is it safe to assume you have tested the desired gun(s) in both calibers and you are accurate with both?
I carry the 45 and use the 9mm for range time and training classes where ammo count is high.
As to the 40, IMHO the 40 is less desirable. It has more kick and not a significant increase in stopping power. Just not a fan of that particular round. I know many like it, I just prefer the 9mm and .45 over it.
Is it safe to assume you have tested the desired gun(s) in both calibers and you are accurate with both?
I carry the 45 and use the 9mm for range time and training classes where ammo count is high.
As to the 40, IMHO the 40 is less desirable. It has more kick and not a significant increase in stopping power. Just not a fan of that particular round. I know many like it, I just prefer the 9mm and .45 over it.