Look, dude... In all seriousness, I can guesstimate by your business sense that you aren't in anything remotely close to what could be considered an economics, sales, or business management field. You may be in service, waste management, or perhaps even manual labor, but at the end of the day, profit may not be possible.
"Fair market value" does not mean cost + profit = selling price. It means "what the market is willing to bear". This may infact be below your margin threshold, equating in a negative margin, but sometimes, it happens.
You solicited for advise, it came. It may not be the desired response, but it's a truthful one.