如何触发在 magento 中收到的付款事件?

You don't need any DB setup since you will not save any new entity. So your config file should look something like the following :

<?xml version="1.0"?>
<config>
    <modules>
        <Moak_Vip>
            <version>0.1.0</version>
        </Moak_Vip>
    </modules>
    <global>
        <models>
            <moak>
                <class>Moak_Vip_Model</class>
            </moak>
        </models>      
        <events>
            <sales_order_payment_pay>
                <observers>
                    <moak_observer>
                        <type>singleton</type>
                        <class>moak/observer</class>
                        <method>checkVipCustomer</method>
                    </moak_observer>
                </observers>
            </sales_order_payment_pay >     
        </events>
     </global>
</config>

现在，您的观察者方法 checkVipCustomer 应该接收一个事件对象，您可以从中检索有关订单、客户...的所有信息，并执行您喜欢的修改.查看 app/code/core/Mage/.../Model/... 中的 Magento 模型类了解如何浏览这些对象.

<?php

class Moak_Vip_Model_Observer
{
    public function checkVipCustomer($event)
    {
        $order = $event->getInvoice()->getOrder(); // Mage_Sales_Model_Order
        /*
            - Check order amount
            - Get customer object
            - Set Group id
            - $customer->save();
        */
        return $this;
    }

}