[Aetae]

<form>
  <ul class="summa">
    <li><p>Опции</p>
      <select id="options">
        <option value="30,70">1</option>
        <option value="25,95">2</option>
        <option value="20,100">3</option>
        <option value="20,100">4</option>
        <option value="20,100">5</option>
        <option value="20,100">6</option>
        <option value="20,100">7</option>
      </select>
    </li>
    <li><p>Диапазон</p><input id="input" type="number" step="0.5" min="30" max="70"  value="30"/></li>
  </ul>
</form>
<script>
  document.getElementById('options').onchange = function(e){
    var input = document.getElementById('input'),
        att = this.options[this.selectedIndex].value.split(',');
    
    input.setAttribute('min', att[0]);
    input.setAttribute('max', att[1]);
  }
</script>