Can you explain where else the cost comes from? I'm thinking here that if a taxi driver's earning, say, $35,000 per year, and you can have two drivers working

Can you explain where else the cost comes from? I'm thinking here that if a taxi driver's earning, say, $35,000 per year, and you can have two drivers working a shift per car, per day, then your labor costs for operating a cab are $70,000 year per car. Assume a car drives ~100k miles per year, gets 25mpg, and gas costs $4/gal. That's $16,000 for gas. How much do the cars cost, and how much maintenance do they need?