What is the difference? ?
Two manufacturers buy components, put on a board they designed (or licensed), write software. The devices provide similar functionality.
Employers colluding on wages (recent issue involving major Silicon Valley high tech companies)
Employees colluding on wages (unionization)
Consumers banding together to dictate price or service (not likely to happen.)
I do have to wonder about manufacturers being able to dictate prices retailers can charge. Is that legit? What if they sell a dominant product, dominant to the point where customers can't conduct business without it (Microsoft Windows, iPhone not quite there yet). What if Tyson foods dominates the beef market. Can they set retail prices?
I think the Walmarts of the world get around that by requesting a model number/features that no one else sells; then it can be a different price.
I recall some manufacturers (Nakamichi) only wholesaled their automobile head units to companies that had in-house installation. I was able to get a package price for entire system, carry-out.
I do understand full-service companies need the revenue to pay for operating costs. Warranty could be reimbursed by manufacturer, regardless of who performs the service (appears SMA has a policy like that.) How much service customers need will depend on quality, intuitiveness, automated and/or remote configuration.
A-la-carte service could be another option. And service contracts. Start-up I worked for paid a third party for Sun service. They raked in the dough while system was reliable, then as HDD starting failing they would replace with a reformatted failed HDD from another customer, which of course didn't last. Caveat Emptor; you're not likely to get what you pay for.
Of course, if you had to price services separately, not getting markup on material, likely you have fewer customers and manufacturer's product gets less customer satisfaction. Which is what you said.
When retailers offer me extended warranty I just laugh and say, "That's what the garbage can is for." Water heater at Home Depo, I asked, "How much?" ($160) I said, "I'll just take a second water heater." (It cost $125)
In a truly free market, the manufacturer would be free to enter such a contract with his retailers.