если я правильно понимаю ваши требования, то вы просто хотите обновить цену с измененным выбором.
пожалуйста, найдите код ниже. может быть полезным для вас.
<table>
<tr>
<td></td>
<form name="m" action="" method="post">
<th> <input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="P2"/>
<label for="purchaseChoice">£5</span> </label>
<input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="P1"/>
<label for="purchaseChoice">£10</label>
</th>
<th class=""> <input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="S111"/>
<label for="purchaseChoice">£20</label>
<input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="S112"/>
<label for="purchaseChoice">£30</label>
</th>
<th class=""> <input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="S131"/>
<label for="purchaseChoice">£40</label>
<input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="S132"/>
<label for="purchaseChoice">£50</label>
</th>
<th class="highlight"> <input id="test" name="purchaseChoice" class="radio" onclick="return togglePrices(this);" type="radio" value="S121"/>
<label for="purchaseChoice">£60</label>
<input id="test" name="purchaseChoice" class="radio" onclick="togglePrices(this);" type="radio" value="S122"/>
<label for="purchaseChoice">£70</label>
</th>
</form>
</tr>
<tr>
<th class="total">TOTAL YOU PAY</th>
<th>
<div class="Priceband"></div>
</th>
</tr>
</table>
<script language="javascript" type="text/javascript" >
function togglePrices(e) {
var price = $(e).val();
$(".Priceband").html(price);
}
</script>