As scout4 mentioned in his thread about 28-gauge ammunition, the small gauges ain't cheap if you're shooting factory ammo. A couple of months ago, I wandered in to the local carriage-trade gun emporium (need a $7000.00 trap gun? They got 'em!) just to see what might be on the used rack, and there on the sale table was a used MEC in .410 bore. Fifty bucks, with half-ounce bar and three bushings, and two bottles. An oldie, steel dies and all. Well, I had just found a Versa-Pack .22/.410 combo, and had invested in a couple of boxes of AA 3" at $15 per. I knew I'd save the hulls, but had no idea I would stumble on a MEC so cheap so soon. Wrote the check and hurried home to see if Graybeard's warnings about .410 reloading woes were true. About five crushed hulls later, I was turning out dandy 2-1/2" loads that threw 5/8-ounce of #7-1/2 pretty dang well. Looked on MEC's website for instructions to convert to 3" hulls, and five weird-looking rounds later had the thing turning out respectable 11/16-ounce loads.
Parents at the local club let their kids shoot .410s at pop cans and such, and they throw the hulls away. Trash can scrounger that I am, I have come up with about 30 Winchester hulls, and even more Federals. Wichester good, Federal not so good. But the cost of shooting the little popgun is really low, if I mail-order wads from Midsouth. A pinch of H110 or Lil Gun, and a tiny charge of shot, and I have a perfect lightweight squirrel-gitter.
The sad part is that, though I'd love to have a 28, I have found a whopping ONE 28-gauge hull in all my scrounging. We don't have a skeet field at my club, so you don't see the 28 much at all. But if you hang around at a club with skeet (or buy bags of once-fired 28 hulls from a club or shop that carries them), you could probably save a bundle shooting the 28. And, it throws a good 1-ounce load, so I have heard. Don Zutz had a 1-ounce recipe in his book Handloading for Hunters, and a recent issue of Handloader had an article on the 28 as a pheasant gun (?), with heavier loads listed.
Anyway -- keep your eyes open at gun shows and sale tables in the local gun shop. A second-hand MEC will save you a bundle on any gauge, but especially if you shoot the little ones.