Reloading for common rounds to be used for plinking really isn't that economical, especially when time is factored in; moreover if you use a single stage like I do.
I may load up a hundred or so to plink, but they are still way more accurate and consistent than any military surplus ammo. In fact, my loads are not that much different that what the marines load for their marksmanship unit. I saw a documentary on it and was surprised to see they use the exact same gear I do. The bulk of what I load is for accuracy and consistency, and care is taken that each round is identical to the last. When I shoot, it is primarily to get the tightest group possible no matter what I am shooting or how I am doing it. Perfect ammo makes this much easier.
For high volume plinking and practice, I like to just use the 10/22. I think it is more fun for shooting cans anyway.
Where handloading and reloading REALLY pays off is when loading for accuracy and consitency, and when loading odd or obscure calibres. I load for the .50 Beo., 10mm, and 6.5 Grendel, in addition to the basics like 5.56, 7.62, 9mm, .40, and .45. I can really come out ahead on the oddballs, and I do on the basics too, but only because I load stuff that is better than the factory ammo with the same bullets. My Hornady pistol ammo is more consistent, just as accurate, and much cheaper; same thing with my 5.56 and 7.62 SMK and T1's. Oh yeah, I can also load stuff that just isn't made. For example, there are only a few different .50 Beo. rounds available, but to the loader there are many, many more.
When comparing prices of ammo, provided you put time and care into making great ammo, you should compare it to the best competition ammo you can find.