Disclaimer: Unpopular opinion and brutal honesty ahead. Possibly sprinkled with a dash of ignorance and doubt.
I think people overestimate the intricacy of tubular mod design. It's' not so much about mechanical design, R&D and innovation as it is about visual design and incorporating tried and trusted (and basic!) mechanical principles. That is, a button. Only if done in a very strange way does visual design require a whole lot of physical prototyping. Read: You don't have to build an entire end-user-quality mod with engravings and all every time you want to check if your latest attempt at a button works as planned. Nor should you use a CNC machine for sketching out visuals.
Some times it feels like the higher price is to kickstart someones dream of turning a hobby into a career just as much as for higher quality and truly clever and thoughtful designs.
I try not to p on anyones parade by mentioning specific models. I'm thinking generally of your average $180+ standard-button mod... not those with unique design features and/or show a passion for the craft. You don't have to re-invent the wheel to impress me, but you better make a darn good one to make me pay a premium for it.
Sounds like I hate the higher priced mods. Truly, I don't. I even own some. Some may be worth it, but definitely not all. Some may have taken a lot of thinking and prototyping, but definitely not all. Some may may be great, but some manufacturers could well have put on their thinking caps a couple more times before going "OK good enough". Life goes on anyway