Hey yes, homemade djo is always much cheaper as long as you are a "good" handyman!
I totally agree with you on the far cheaper.
Then be a little bit good handyman, then not really.
I'm not at all of the game, but my principle is "whoever wants, can" and "at birth we just know how to cry, pee poo, everything else we learn". Especially today thanks to the internet we can have access to all the information.
I had never create a ceiling / floor, never ask 1m calico ...
We take time, we think, is documented ... and you get there.