I need to convert result of this function to number:

const [nbChambres, setNbChambres] = useState(1);
const [nbNuits, setNbNuits] = useState(1); 

function calculatePrixTotal(){
    const nbChambresInt = parseInt(nbChambres) || 1;
    const nbNuitsInt = parseInt(nbNuits) || 1;
    let priceNumber = price.substring(1);

    if(priceNumber.includes(',')) {
        priceNumber = parseInt(priceNumber.replace(',', ''));
        const prixTotal = String(priceNumber * nbNuitsInt * nbChambresInt);
            return prixTotal.slice(0, prixTotal.length - 3) + "," + prixTotal.slice(prixTotal.length - 3);
    } else {
        return String(parseInt(priceNumber) * nbNuitsInt * nbChambresInt);
    }
}

Here is the function I made to make the subtraction, I got NaN as the result:

function calculateNewMoneyBalance(){
    const calcInt = parseFloat(calculatePrixTotal);
    const moneyInt = parseInt(MoneyBalance);
    console.log(typeof moneyInt);
    return parseInt(moneyInt - calcInt);
}