Clever people can do a lot, even with a very low budget. But be skeptical before you imitate, especially if there's no photos of finished setup or product.
This "kiln' might be able to low-fire some clay mixtures, but if you want real, hard, durable ceramics, you need a more serious approach. Or, a pit in the dirt can produce very basic ceramics, without the kiln-build effort.
Nice video of building a more elaborate and reliable ceramic kiln:
https://www.youtube.com/watch?v=iAUSZoijbwo