JavaScript6.js

function updatePrice() {
  let s = document.getElementsByName("productType");
  let select = s[0];
  let price = 0;
  let prices = getPrices();
  let priceIndex = parseInt(select.value) - 1;
  if (priceIndex >= 0) {
    price = prices.prodTypes[priceIndex];
  }
  
  let radioDiv = document.getElementById("radio-product-specifics");
  radioDiv.style.display = (select.value === "3" ? "inline-block" : "none");
  
  let radios = document.getElementsByName("radioOptions");
  radios.forEach(function(radio) {
    if (radio.checked) {
      let optionPrice = prices.radioOptions[radio.value];
      if (optionPrice !== undefined) {
        price += optionPrice;
      }
    }
  });

  let checkDiv = document.getElementById("checkbox-product-specifics");
  checkDiv.style.display = (select.value === "3" ? "none" : "inline-block");

  let checkboxes = document.querySelectorAll("#checkbox-product-specifics input");
  checkboxes.forEach(function(checkbox) {
    if (checkbox.checked) {
      let propPrice = prices.prodProperties[checkbox.name];
      if (propPrice !== undefined) {
        price += propPrice;
      }
    }
  });
  
  let prodPrice = document.getElementById("result");
  prodPrice.innerHTML = price + " рублей";
}

function calculate() {
  let regexp = /\D/g;
  let productAmount = document.getElementsByName("product-amount")[0].value;
  let r = document.getElementById("result");

  if (Boolean(productAmount)) {
      if (regexp.test(productAmount)) {
         r.innerText = "Данные введены не корректно";
      } else {
          regexp = /\d/g;
          productAmount = parseInt(productAmount.match(regexp).join(""));
          let productPrice = r.innerText.match(/\d+/g);
          r.innerText = `${productPrice * productAmount} рублей`;
      }
  }
  return false;
}

function getPrices() {
  return {
      prodProperties: {
          checkOptionsB: 5,
          checkOptionsC: 10,
        },
      prodTypes: [100, 200, 150],
      radioOptions: {
          option2: 30,
          option3: 90,
      }
  };
}

window.addEventListener("DOMContentLoaded", function (event) {
  let radioDiv = document.getElementById("radio-product-specifics");
  radioDiv.style.display = "none";
  
  let s = document.getElementsByName("productType");
  let select = s[0];

  select.addEventListener("change", function(event) {
    let target = event.target;
    console.log(target.value);
    updatePrice();
  });
   
  let radios = document.getElementsByName("radioOptions");
  radios.forEach(function(radio) {
    radio.addEventListener("change", function(event) {
      let r = event.target;
      console.log(r.value);
      updatePrice();
    });
  });

  let checkboxes = document.querySelectorAll("#checkbox-product-specifics input");
  checkboxes.forEach(function(checkbox) {
    checkbox.addEventListener("change", function(event) {
      let c = event.target;
      console.log(c.name);
      console.log(c.value);
      updatePrice();
    });
  });

  updatePrice();

  let button = document.getElementById("calculate-button");
  button.addEventListener("click", calculate);
});