Calculs automatique

[EricDEV]

Bonjour j'aurais besoin d'aide. J'aimerais que quand je choisisse un nombre dans ma liste sa me mette automatiquement le prix total en dessous.

voici le code :

<div class="sg-row">
                    <div class="sg-col-20-of-24 sg-col-28-of-32 sg-col-16-of-20 sg-col sg-col-32-of-36 sg-col-8-of-12 sg-col-12-of-16 sg-col-24-of-28">
                            <p style="
                                        font-weight: bold;
                                        font-size: 25px;
                                     ">
                                Kit Minage
                            </p>
                        <div class="sg-col-inner">
                            <p style="
                                      font-weight: bold;
                                      font-size: 20px;
                                      color: red;

                                     ">
                                <span id="price_inside_buybox" class="a-size-medium a-color-price">
                                    85.000&nbsp;$
                                </span>
                            </p>
                                <select name="quantity" autocomplete="off" id="quantity" tabindex="0" class="a-native-dropdown">
                                    <option value="1" selected="">1
                                    </option>
                                    <option value="2">2
                                    </option>
                                </select>
                                <span tabindex="-1" class="a-button a-button-dropdown a-button-small" id="a-autoid-0" aria-hidden="true" style="min-width: 0%;">
                                    <span class="a-button-inner">
                                        <span class="a-button-text a-declarative" data-action="a-dropdown-button" role="button" aria-hidden="true" id="a-autoid-0-announce">
                                            <span class="a-dropdown-label">
                                                Quantité :
                                            </span>
                                            <span class="a-dropdown-prompt">
                                                1
                                            </span>
                                        </span>
                                        <i class="a-icon a-icon-dropdown"></i>
                                    </span>
                                </span>

                                <div id="quantityAwarePriceRelocate_feature_div" class="feature" data-feature-name="quantityAwarePriceRelocate" data-cel-widget="quantityAwarePriceRelocate_feature_div">
                                </div>

                                <div id="soldByThirdPartyRelocate_feature_div" class="feature" data-feature-name="soldByThirdPartyRelocate" data-cel-widget="soldByThirdPartyRelocate_feature_div">
                                    <div id="soldByThirdParty" class="a-section a-spacing-small a-text-left">
                                        <span class="a-color-price price3P" dir="ltr">
                                            $ 85.000
                                        </span>
                                    </div>

                                </div>

                        </div>
                    </div>
                </div>

J'aimerais que quand la quantité augmente le deuxième 85.000$ se multiplie par la quantité choisi ...

Il me faudrait juste un code script normalement ...