Make the result useful
Show each charge and credit separately
Move-in funds are easier to understand when first rent, deposit, fees, and credits are itemized. The sum is not a statement about what charges are lawful.
Use confirmed lease terms and local rules for timing, disclosures, and refundable treatment.
Worked scenario
$1,800 first rent + $1,800 deposit + $150 fee − $100 credit equals $3,650 due in the modeled scenario.