<label>
<input type="radio" name="wpcc_structure[2]" value="300" checked class="wpcc_jq_action wpcc_jq_action_2" data-type="radio" data-fid="2" data-data="data"> Стартовый набор
<div class="images"><img src="tovar1_price.png"></div>
</label>
input:checked + .images{
border: 2px solid red;
}