Having an adversarial relationship with your suppliers is not necessarily the best arrangement. It means that suppliers will nickel-and-dime you for every change and ship minimum possible quality to you. The cost of loss of agility and quality will impact your bottom line.

My family operated a business on exactly these razor thin margins. You always live on the razors edge. You're unable to invest into the future, unable to improve your processes, and god forbid there is even a minor disruption. I don't think it's sustainable. We've since faltered, as have our many of our competitors and suppliers.

The value in being a supplier is you make the replacement parts when they start breaking in 5-10 years. The real money is in selling to every auto parts store in the country.