Harris Horticulture provides and maintains live plants in office buildings. The company's 850 customers are charged $40 per month for this service, which includes weekly watering visits. The variable cost to service a customer's location is $20 per month. The company incurs $2,000 each month to maintain its fleet of four service vans and $3,000 each month in salaries. Harris pays a bookkeeping service $3 per customer each month to handle all invoicing and accounting functions.