If there is anyone that is just getting into reloading, there is a good deal on the electronic calipers at Canadian Tire. Just bought one today for $9.99. If they are out of stock, ask for a rain check.
I already had a similar one that I had purchased a number of years ago from Princess Auto. Both are of similar quality. The Canadian Tire one only measures in millimeters and decimal inches, while the Princess Auto version measures in fractions of an inch as well. Both of them use the small LR44 watch battery. I always keep a spare in my caliper case.
They will not be in the quality range of something like a Starrett or Mitutoyo brand, but definitely good enough for reloading.
If it is something that you need, go check them out!