9mm brass will reload almost forever. I've been using the same 9mm brass for 3+ years, and I reload and shoot a lot. With 9mm, I do not factor in the cost of brass because 9mm brass is free for me. 99% of people at the range throw it away, and the range guys let me sweep up the brass around me. My 9mm brass collection grows every time I go to the range.
223 brass I throw out after about 5-10 reloadings. I reload 223 in batches of 1000 pieces of brass. After a while, I'll start seeing cracks in the neck. Once I start to see cracks, I throw out the entire batch.
I can't comment on 308 brass in a title 1 gun. I reload lots of 308, however, for my specific guns, 308 lasts for 2 reloadings. I shoot 308 out of open bolt belt feds, and belt feds have larger than normal chambers, and their feed and extraction is quite violent, so they tear up 308 brass. If I try to reload a third time, I encounter problems, specifically broken cases. Rather than throw out the cases, and since I prefer not to sell the brass, I give the brass away. The brass is usually good for one more reloading to be used in a bolt action only (the guys who accept the brass are confident they can extract the broken case, even if it does break).
If you're getting into reloading to save money, you won't save money. You will spend less per round, and you'll save money per round, but you will shot a lot more. A whole lot more.
Every time I go to the range, it is always the reloaders who have the most ammo and stay the longest. I am uncomfortable going to the range with less than 1000 rounds. In my 20+ years of shooting, I've never seen a factory ammo shooter with 1000 rounds.
I can also tell which reloader owns a progressive press by how fast they shoot.
Welcome to the hobby. It's an awesome and fun hobby. Be safe and enjoy.