WTF! for the price they asking on aliexpress for such a "products", especially first one. if you plan DIY the rest with wood maybe you can do the whole thing just to save about 5 to 50 times.

Just cut a generic case + paint job and you will have a similar one and cheaper.

OP's name checks out: willing to pay higher and higher prices for lesser and lesser material.

I haven't seen any case that houses 3 or more ATX systems. Many people settle for using a server rack/cabinet to house multiple systems. Yet depending on which ATX cases this solution replaces, the server rack may actually be a less efficient use of space and a detriment to thermal performance.

How often are you looking to swap parts and systems? Are you choosing open-air cases because you need ready frequent access to the hardware?

This? It was good enough for google

Well... The reason why I ask for that kind of casing that could stack on top of each other, is because I wanted to play with the hardware in real time.

thus The screenshot you provided is overkill! HAHAHAH! 😀

Anyway, I decided to just stick with Test Bench, and stack them up together.

Thanks for your inputs on this. 😀