Are cheap rocket stoves worth my time?

I'm thinking of purchasing a small portable rocket stove such as this one: https://www.amazon.com/Cooking-Portable-Burning-Camping-backyard/dp/B0BZ4D72QF/ref=sr_1_4?crid=11NGT4XKC6HP7&keywords=rocket+stove&qid=1692144338&sprefix=rocket+stove%2Caps%2C505&sr=8-4 or this one: https://www.amazon.com/Outdoor-Camping-Portable-Chamber-Carrying/dp/B0B55MZ3ST/ref=sr_1_8?crid=11NGT4XKC6HP7&keywords=rocket+stove&qid=1692144338&sprefix=rocket+stove%2Caps%2C505&sr=8-8

My goals would be to:
1. Cook grain on it and be able to finish the cooking PEP badge. I'm already confident cooking on an open fire.
2. Have it as a backup cooking implement for SHTF. I live in north Texas and S indeed HTF a couple of years ago.
3. Fun with friends cooking stuff on the back porch.

I'm not familiar with RM stoves. Is something like this worth my time to experiment with? Is it likely to just fall apart on me? How cheap and easy would it be for a newbie to construct a small RM stove so it's not worth buying one?

I'd just throw one together out of brick, or take some fun time to make one out of cob. You can usually find the materials for cheap/free and have something that works better than the one you are looking at.

https://permies.com/t/137193/bricks-simple-rocket-stove

Daniel Ray wrote:I'd just throw one together out of brick, or take some fun time to make one out of cob. You can usually find the materials for cheap/free and have something that works better than the one you are looking at.

That's my take as well. If you buy something, it's just another thing. But that's not all bad -- it's a thing that is useful in a pinch.

But then again, if you scrounge materials and tweak it to make it work, you will have gained a skill that travels anywhere and lasts a lifetime. The world is full of free stuff; skills make the difference. My 2c.

Just remember that it will open a massive rabbit hole in your life ;)

One of the criteria for a rocket stove is that the riser be insulated.  This allows a higher heat in the riser to enable to combustion of secondary gases.
That thing doesn't look like it's insulated, but if you could insulate it, it would work more in lines with the principles of a rocket stove.

I agree with Graham (welcome back Graham) it is worth getting the best from a rocket stove by using insulation in the right places.

Graham Chiu wrote:One of the criteria for a rocket stove is that the riser be insulated.  This allows a higher heat in the riser to enable to combustion of secondary gases.
That thing doesn't look like it's insulated, but if you could insulate it, it would work more in lines with the principles of a rocket stove.

I have personally witnessed the excitement of a friend after getting one of these square steel tubing 'K stoves' only to be followed by disappointment when it couldn't successfully produce a complete burn without added insulation. You can do much better with used bricks from the junkyard, but it is hard to deny the portability factor if that is a draw for you. Depending on the situations you find yourself in, I have used the Dakota Fire Hole technique to good effect - not quite full rocket, but better than a 3-stone fire - without any equipment needed.

For shtf and not much for pretty, a few concrete blocks (between 3 & 6, depending upon stove design) appropriately arranged will provide similar cooking options. My guess is you can find the blocks for free.  

I get the impression that the K-stoves on Amazon etc. have a riser that is waaaay too short for a complete burn. They should be 3x that height.

I dont think the original rocket stoves were very insulated by today's standards
Certainly pocket rockets were not insulated, and they were made entirely of metal.
Little Aussie Rockets and  Green Shortz  have some good content on metal rocket stoves that seem to burn as least as clean as those made of basic bricks.
They also offer metal rockets for sale.
I'm all about the both/and when it comes to tools.
Both buying a basic version and making a more advanced version is usually how this goes for me, but I did recently spring for a couple of real griddles after futzing around with some stainless steel pans.