Depends on what you're trying to accomplish by reloading. If it's targets and a 12 gauge, 1oz (or less) will do the job. A 25# bag of shot will give you 400 reloads. Depending on the powder, your charge will run somewhere around 18 grains. There are 7000 grains in a pound, so that equates to about 388 rounds. Then there are primers, hulls and wads.
A MEC Jr. is a solid beginner reloading machine. (After almost 30 years, I still use two of them), but progressives are available that cost from around $400 to as much as $1500.
Depending on your volume of shooting, it may or may not makes $$$ sense to do this. If you're talking about shooting a few boxes to warm up for pheasant, and you shoot a few boxes at that, reloading is NOT worth the effort. If you're like me and shoot 200-250 rounds each time I go to a club, (about once a week), then it begins to make sense. If you're a serious competitor who shoots 20,000 rounds a year (and you don't have the money to buy shells but do have the time), then it really makes a lot of sense.
What's your purpose?