Jack Burgess hit it on the head when he points out that you get what you pay for: the Harbor Freight and similar are commodity grade or less calipers and if one is into disposable instruments, these can certainly be useful.
I have six calipers, Mititoyo, Helios (German), Brown & …..? (Swiss), none of them new, all extremely accurate, and none…none at all depending on batteries. I use dial calipers routinely, but use only vernier calipers to check on critical measurements. I learned my lesson on the latter some years ago when I found to my chagrin that I could find no one, nada, zip, that would even consider, much less touch a repair on any of the digital calipers (“throw them out”). I also learned that to a man, the fine instrument repair shops use only vernier calipers to check accuracy in their work.
My core instruments are almost all the very best I can find, and in that regard, they have paid, and continue to pay for themselves in accuracy, wear, longevity, and usefulness over the years- the ultimate economy.
Denny S. Anspach MD