"Whack a Mole" reloaders are an option, if you're loading ONLY shells that have been fired in your
manually-operated shotgun. If you shoot an auto-loader, or have hulls fired in other shotguns, they're not likely to work. These tools don't resize the base, so you run the chance of not being able to chamber the shells.
version. Seems decent, haven't tried one. I contacted the manufacturer last year, with some questions. End result: His tools have the same limitations as the Lee Loader.
(scroll down a couple paragraphs) Discontinued, but can be picked up for $15-30 on auction sites or $5-20 at yard/garage sales. (I snagged one for about $18 on eBay.) It works, but not well. Wad seating pressure and crimps are difficult to keep consistent. And, the lack of base-sizing got me in trouble, even with some hulls fired in my own shotgun.
There are a few 12 ga Ideal hand tools floating around, but they're hard to find and pricey. I haven't ever even seen one in person.
Other than that, you're pretty much stuck getting a press.
For casual reloading and loads that won't be taken too seriously, the Lee Load-All is fine. The newer Lee Load-All II is easier to get your hands on, but I have come to prefer the older version (even with its cheesy "aluminum" base). I picked up a '60s-'70s vintage original Load-All for about $30, shipped, with all of the original powder and shot bushings. I clamp it to a piece of plywood when I use it; and throw 20-30 lbs of shot/bullets on the wood, to weigh it down.
Either version is actually fairly compact. So, storage isn't difficult. Your wads, hulls, shot, powder, and primers will take up at least 5 times as much space as the press.
I would very much rather have a proper shot shell press; but for what I do... the Load-All gets 'er done.
As for cost...
Other posters had a very good point. The "savings" margin is really slim for 12 ga and 20 ga. But, you can make it worthwhile by using non-name-brand components. I use Claybusters and Ballistic Products (BPI) wads, and reclaimed shot.
That still only saves me about $1 to $1.25 per box. But, to me, it's worth it; even if other shooters think it's trivial, when considering the time and labor involved.
(You see, wncchester, I'm not an elitist that hates all Lee products. The Load-All is one I happen to like, when you understand its intended purpose.)