Interactive pricing card made with HTML5/CSS3 and Vanilla Javascript

Hello Nneoma! Great work!

You can refactor your code like this

function applyDiscount(discount){
  price.textContent = discount;
  timeout();
}

function discountToggle() {
  checkboxSlide.addEventListener("click", () => {
    if (checkboxSlide.checked === true) {
      if (price.textContent == amount[0]) applyDiscount(discount[0]) 
      else if (price.textContent == amount[1]) applyDiscount(discount[1])
      else if (price.textContent == amount[2]) applyDiscount(discount[2])
      else if (price.textContent == amount[3]) applyDiscount(discount[3])
      else applyDiscount(discount[4])
    } else {
      price.textContent = rangeSlide.value;
    }
  });
}

function updatePrice(amount, views){
  price.textContent = price
  pageviews.textContent = views;
}

function rangeOfViews() {
  // range slide listener
  rangeSlide.addEventListener("input", (e) => {
    rangeValue.innerHTML = e.target.value;
    if (rangeSlide.value === 10000 || rangeSlide.value < 50000) updatePrice(amount[0], views[0])
    else if (rangeSlide.value === 50000 || rangeSlide.value < 100000) updatePrice(amount[1], views[1]);
    else if (rangeSlide.value === 100000 || rangeSlide.value < 500000) updatePrice(amount[2], views[2]);
    else if (rangeSlide.value === 500000 || rangeSlide.value < 1000000) updatePrice(amount[3], views[3]);
    else updatePrice(amount[4], views[4]);
  });
}

I hope it helps! Cheers!