Adding Two Conditions to an IF Statement

QUESTION 2

If someone selects the "First time buyer" checkbox (firstTimeBtn) the "firstBuyer" values should be returned, however, in addition to this, "firstBuyer" values should only be returned when the house price is £500,000 or under. If the house price is over £500,000 "standBuyer" values should be returned instead.

From Data Controller Module:

getBuyerType: function() {
            const covidBtnCheck = document.getElementById(DOMstrings.covidBtn)
            const firstTimeBtnCheck = document.getElementById(DOMstrings.firstTimeBtn)
            const secondPropBtnCheck = document.getElementById(DOMstrings.secondPropBtn)

            if (covidBtnCheck.checked && secondPropBtnCheck.checked) { 
                return 'secondCovidBuyer';
            } else if (firstTimeBtnCheck.checked) {
                return 'firstBuyer';
            } else if (secondPropBtnCheck.checked) {
                return 'secBuyer';
            } else if (covidBtnCheck.checked) {
                return 'covidBuyer';
            } else {
                return 'standBuyer';
            }
        },
    }

AND

 let checkBuyerType = function() {
        let buyerType = UICtrl.getBuyerType();
 if (buyerType == 'secondCovidBuyer') {
return dataCtrl.secondCovidBuyer;        
} else if (buyerType == 'firstBuyer') {
            return dataCtrl.firstBuyer;
        } else if (buyerType == 'secBuyer') {
            return dataCtrl.secBuyer;
    } else if (buyerType == 'covidBuyer') {
            return dataCtrl.covidBuyer;
        } else {
            return dataCtrl.standBuyer;
        }
    }

Originally, I tried adding "&& (houseCost <= 500000)" into the getBuyerType script within the "else if (firstTimeBtnCheck.checked) { return 'firstBuyer';" line, but it doesn't work. Wondering if it's because I should be using housePrice instead of houseCost? Including the below code for context, in case it is helpful:

  //1. Get the cost of the house
        houseCost = UICtrl.getInput().housePrice;
        //2. Only proceed if there is a house cost
        if (houseCost >= 0) {

QUESTION 1 (SOLVED)

I have 3 checkboxes and each checkbox returns different numerical values in a table. However, I want to add another option so that if both 'covidBtn' AND 'secondPropBtn' are selected, it will return 'secondCovidBuyer' values. I would really appreciate it if anyone is able to help me! Thank you.

Return Values

// Different tax percentages and taxBand data
  standBuyer: [0, 0.02, 0.05, 0.05, 0.05, 0.10, 0.12],
  firstBuyer: [0, 0, 0, 0.05],
  secBuyer: [0.03, 0.05, 0.08, 0.08, 0.08, 0.13, 0.15],
  covidBuyer: [0, 0, 0, 0, 0.05, 0.10, 0.12],
  secondCovidBuyer: [0.03, 0.03, 0.03, 0.03, 0.08, 0.13, 0.15],
  taxBand: [0, 125000, 250000, 300000, 500000, 925000, 1500000, Infinity],

Function

getBuyerType: function() {
            if (document.getElementById(DOMstrings.firstTimeBtn).checked == true) {
                return 'firstBuyer';
            } else if (document.getElementById(DOMstrings.secondPropBtn).checked == true) {
                return 'secBuyer';
    } else if (document.getElementById(DOMstrings.covidBtn).checked == true) {
                return 'covidBuyer';
            } else {
                return 'standBuyer';
            }
        },