$200k/month in used cars? If one car goes for $30,000 - what's the profit margin on that? And then how many sales does he have per month?

Used cars are very hard to judge these things. You can't just assume "GROSS = PROFIT," and "More Gross = More Profit." I had a client who delivers gas to gas stations that was doing $74mm in revenue a year, but his profit margins are so low that he got rejected from everywhere.