Custom Inner Fender Braces 67-76

All cage "kits" are made from HREW tubing...the cheapest stuff you can get. If they were made of DOM, they would definitely flaunt that. DOM is just as expensive as chromoly.
The difference is HREW(Hot Rolled Electric Welded), has a weld seam down the length of the tubing. DOM does not have this. The welded seam is obviously not as strong, and in some cases, the tubing can split along this seam(like when off road guys are beating on the tubing and what not).
It would be hard for anyone to compete with the big companies that have a CNC bender and bend tubes all day long. On the flip side of that...you will be buying a universal type of cage. One that may fit your Mopar, but probably will also fit in a Camaro, Vega, maybe a Mustang, etc. With this comes poor fitment, tubes that are very visible from outside the car, etc.