Walmart has "CAP Cast Iron Kettlebells", for less than a dollar per pound:
Free shipping on orders over $35: and free ship-to-store, if you have a Walmart close to you and you can go pick it up.
They're denoted in pounds
, not kg. But they go up to 60# (~27kg), 70# (~32kb) and 80# (~36kg), so they have most of what you'll need, even if the units are wrong.
This is not a review, more of a heads-up. I've held one of these in the store, but I haven't used one. The shape is more Dragon Door than competition. On first impression, the finish seems fine for swings and gets ups, so S&S practitioners ought to be able to use them. People entering the kettlebell will probably be able to press them just fine. Not sure about high-rep snatches or LCCJ for the gireviks among us. But they're not competition-shaped anyway, so that might be moot.
Walmart is also an outlet for Kettlebell Kings competition-style bells. Not sure if there's any savings there – maybe on shipping? Shipping is a pretty significant cost-item for kbs.