A box of 50 on a single stage press is 20-25 minutes without rushing. A box of 50 on my Loadmaster (or a similar progressive) with prep time to add powder & brass to case loader = 10 minutes. If I keep going that drops to 5 minutes per 50. Hardly a major time expenditure. I can't think of too many jobs where a person couldn't find an hour a week to load up 150-400 rounds. At a savings of $10/box that's a minimum of $30-80 savings per loading session which for most people isn't chump change. Cast your own bullets and the savings jump a minimum of an additional $5-6/box.
Of course casting also takes time and an initial cash outlay for equipment but with the price of bullets (9mm is a minimum of $100/1000 these days) it does not take too long (perhaps 3000-4000 bullets) to recoup those costs. After that you're basically casting for the cost of the lead so maybe 2 cents per bullet for 9mm if you're buying the lead for $1/pound.
If you shoot a box a month reloading probably isn't worth it but if you shoot even one box of 9mm per week that's a savings of at least $500 per year and much more than that if you're into 38's, 44's or 45's.
I enjoy reloading for handgun and rifle, but if I am truly honest about the total amount of time I spend doing everything associated with it, the cost savings are usually a minor part of the equation.
Thanks for suggesting some real numbers, that provides useful context. They do seem a bit on the optimistic side (for most people), but I have no trouble believing that a talented and organized person could get there: You've got your techniques and equipment dialed in, and maybe you have a dedicated space to keep your equipment set up and have components easily accessible. For somebody starting out, that's not likely to be the case.
I think it's very easy to underestimate how much time is actually put in to reloading. You almost never hear about time spent doing the behind the scenes stuff - Those things that are not directly related to "production reloading". It takes time to research, choose, and then shop for equipment and components. Then there's time spent learning basic techniques and setting up your equipment and reloading area. And time spent researching load data and then testing loads. There are probably other points I'm missing. Oh, and how about time spent collecting and processing brass? How many times have you seen someone write that they use "free" range brass?
And yes, casting sounds like a great way to save. But again, there's not typically any mention of how long it takes in production terms. And almost never any discussion of how much time is spent behind the scenes.
If you love reloading, and that's a hobby that you choose (like I do), then great. You'd probably make a different cost/benefit calculation from someone who loves shooting and is indifferent to reloading (or someone who dislikes reloading). Or someone who, on a good week, maybe only has two hours per week available for their shooting hobby (and everything associated with it).