...it depends on your laser/plasma/shear
A cnc cutting option (plasma or laser) easily might be your cheapest option ..avoiding coping and incorporating slot tabs can reduce your production costs drastically even if you cut time is fractionally longer.
What is cheaper varies wildly depending on equipment. If you have a 10k Fiber Laser you can cut these flats faster than you can shear them.
You cant exclusively cut this with any single machine so its hardly a showcase. You have tubing that needs a tube laser or a saw...you have angle that needs a laser/plasma/shear cutting or a saw that cuts angle.
The only way this is a showcase on a laser ready design is if you have both a sheet laser and a tube laser...
I'm not trying to rip you down, but you can redesign this to be made exclusively out of sheet if you incorporate more channel/angle shapes into your design and truly cut them on one machine. Further improvement (for manufacturing) can come from slot tabbing parts together so it self fixtures itself.