Greetings,
I'm the creator of the Hot-Pot. Thanks for your interest in our product. Since I'm not a Sponsor on this site, I don't know how much I can say about it but maybe I can answer a couple questions.
If you want too make your own Hot-Pot, just go to Walmart and buy the following stock pots:
#553412467 Mainstay 16 qt stainless steel stock pot with metal lid $11.94
#552022569 Mainstay 12 qt stainless steel stock pot with metal lid $8.94
Make sure you get the ones with the stainless lids, not the glass lids. The ring that holds the inner pot is made out of the lid from the larger pot. You'll need a way to cut the center out of the lid to fit snugly around the inner pot. Slide it up till it stops against the handles. Now drill 24 equally spaced 9/16" holes just below the ring. I have a pile of pots with different sizes and numbers of holes that I tried during the development of the Hot-Pot, but the configuration I just described seems to give the best/brightest flame.
When I was making my prototypes, I just cut the slots in the bottom of the inner pot with a hand held plasma cutter. The hand made slots work just as well as the CNC cut ones, but they didn't look uniform or professional enough to sell to the public. Cut slots as close together as you can, but try not to break through to adjacent slots as this will ruin the integrity of the bottom and allow pellets to fall through. The air holes in the outer pot are not critical, as long as they add up to at least 6 square inches of area. They can be drilled, plasma cut, or whatever you want. Keep the bottoms of the holes about 2" above the bottom of the pot so the ashes that fall through will be contained in the outer pot.
The flame concentrator ring is not super-critical. Just make it overhang the inner pot about an inch to inch and a half. This ring helps with the chimney effect and makes the flame more consistent.
That should be all you need to know. Yes, it's a fair amount of work to save a hundred bucks, but if you're anything like me, the satisfaction of making something yourself is worth quite a bit.
As far as cooking goes, a Hot-Pot makes plenty of heat, but as Ragman mentioned, soot build-up makes quite a mess on your cookware. I don't cook over campfires for that reason. If you are used to dealing with the soot, there's no reason you couldn't cook over a Hot-Pot.
If you have any other questions, feel free to PM me and I'll answer as best I can.
Cheers!
SilverBob