Why don’t you build a kit from Madisound if you have not done so already? It can answer some of your recurring questions.
I’ve sourced parts from Madisound for 22 years and been designing and building my own speakers for 42 years. Came close to resurrecting and building a speaker company at one point. Decided its too costly to do really well in less than 2-3 years. Takes more like 5-10 years or more like you see with the better boutique builders.
You might be confused comparing hobbyists with business.
Hobbyists put no cost on their time and labor of love. Labor is free.
Businesses are in business to make profit, to evolve, and stay in business. There is a cost to doing business.
If you want to save money, buy good used speakers, recondition them. It’s cheaper, may be an option for you.
If you know of someone who buys parts and builds new quality speakers for FREE at no labor cost, please share their name and contact info.