<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>