The other day I saw something called the stump stove. This is a good example of taking advantage of someone. It is a small log approximately 6 to 12 inches in diameter and up to about 20 inches high. It comes in different sizes. There is a hole cut halfway through the center. The idea is you light it on the inside and it burns for several hours. You can cook over it and as it burns down it becomes a campfire.
The principal is not bad. It is similar to the rocket stove and will burn as advertised. If you made your own out of free wood it will work in a fixed camp site.
The problem is the price. They are selling them as the new green way to cook and have a campfire. The only green I can see about the whole thing is the green that goes into their pockets. A 6×10 inch log costs $15.00 plus shipping. An 8 x 12 inch log cost $20.00 plus shipping and burns up to 4 hours. Two of their 8 x 12 inch stoves would cost $62.00 delivered to my house. For that amount of money I can get something worthwhile, like this stove
They seem to have found buyers for these logs, I saw one the other day. Take a look at the pictures. It is a simple idea that will cook your food, but the cost is ridiculous. If you want to see them just look up stump stove on the internet.