Edit in JSFiddle

function proRangeSlider(sliderid, outputid, colorclass) {
        var x = document.getElementById(sliderid).value;  
        document.getElementById(outputid).innerHTML = x;
        document.getElementById(sliderid).setAttribute('class', colorclass);
        
        updateTotal();
}

var total = 0;
function updateTotal() {
        var list= document.getElementsByClassName("range");
        [].forEach.call(list, function(el) {
            console.log(el.value);
            total += parseInt(el.value);
        }); 
        document.getElementById("n_total").innerHTML = total;
      
}
$.fn.serializeObject = function()
{
    var o = {};
    var a = this.serializeArray();
    $.each(a, function() {
        if (o[this.name] !== undefined) {
            if (!o[this.name].push) {
                o[this.name] = [o[this.name]];
            }
            o[this.name].push(this.value || '');
        } else {
            o[this.name] = this.value || '';
        }
    });
    return o;
};

$(function() {
    $('form').submit(function() {
        $('#result').text(JSON.stringify($('form').serializeObject()));
        return false;
    });
});

<form action="" method="post">
    
    <div id="proRangeSlider">
    <div id="total">TOTAL: <span id="n_total"></span></div>
    <div>
        <input type="range" name="costPerDay" class="range orange" id="rangeSlider1" value="20" oninput="proRangeSlider(this.id, 'output1', 'orange')">
        <output id="output1">20</output>
    </div>
    
    <div>
        <input type="range" name="numberOfDays" value="20" id="rangeSlider2" class="blue range" oninput="proRangeSlider(this.id, 'output2', 'blue')">
        <output id="output2">20</output>
    </div>
        
    <div>    
        <input type="range" id="rangeSlider3" name="designCost" value="40" class="red range" oninput="proRangeSlider(this.id, 'output3', 'red')">
        <output id="output3">40</output>
    </div>
        
    <div>
        <input type="range" id="rangeSlider4" name="cmsIntegration" value="64" class="purple" oninput="proRangeSlider(this.id, 'output4', 'purple')">
        <output id="output4">64</output>
    </div>
    
    <div>    
        <input type="range" id="rangeSlider5" name="seoContentStrategy" value="75" class="gray range" oninput="proRangeSlider(this.id, 'output5', 'gray')">
        <output id="output5">75</output>
    </div>
</div>       
<p><input class="submit" type="submit" /></p>
</form>
<h2>JSON</h2>
<pre id="result">
</pre>

body,
html {
  margin: 10px;
  padding: 10px;
  text-align: center;
}
#proRangeSlider {
    border: 1px solid #CCC;
    padding: 0;
}
div {
    background: #f1f1f1;
    border-bottom: 1px dotted #666;
    padding: 15px 0px 15px 0px;
}
div:last-child {
    border: none;
}
h1 {
  color: #ecf0f1;
  text-align: center;
  font-size: 40px;
  margin: 0px;
  height: 70px;
}

input {
  -webkit-appearance: none;
  width: 160px;
  height: 20px;
  margin: 10px 50px;
  background: linear-gradient(to right, #16a085 0%, #16a085 100%);
  background-size: 150px 10px;
  background-position: center;
  background-repeat: no-repeat;
  overflow: hidden;
  outline: none;
  zoom: 130%;
  display: block;
  margin: auto;
  margin-bottom: 30px;
}
 input::-webkit-slider-thumb {
 -webkit-appearance: none;
 width: 20px;
 height: 20px;
 background: #27ae60;
 position: relative;
 z-index: 3;
}
 input::-webkit-slider-thumb:after {
 content: " ";
 width: 160px;
 height: 10px;
 position: absolute;
 z-index: 1;
 right: 20px;
 top: 5px;
 background: #2ecc71;
}
 .green::-webkit-slider-thumb {
 background: #27ae60;
}
 .green::-webkit-slider-thumb:after {
 background: #2ecc71;
}
 .red::-webkit-slider-thumb {
 background: #c0392b;
}
 .red::-webkit-slider-thumb:after {
 background: #e74c3c;
}
 .blue::-webkit-slider-thumb {
 background: #2980b9;
}
 .blue::-webkit-slider-thumb:after {
 background: #3498db;
}
 .orange::-webkit-slider-thumb {
 background: #d35400;
}
 .orange::-webkit-slider-thumb:after {
 background: #e67e22;
}
 .purple::-webkit-slider-thumb {
 background: #8e44ad;
}
 .purple::-webkit-slider-thumb:after {
 background: #9b59b6;
}
 .gray::-webkit-slider-thumb {
 background: #7f8c8d;
}
 .gray::-webkit-slider-thumb:after {
 background: #95a5a6;
}
output {
    
}

.submit {
    border: none;
    padding: 4px;
    width: auto;
    background: orange;
    text-transform: uppercase;
    color: #FFF;
    font-family: sans-serif;
    cursor: pointer;
}