目的在于履行订单,.代表买方来支付完全是意译啊on behalf and at the cost of the purchaser
要分成on behalf of the purchaser和at the cost of the purchaser两部分来理解就容易多了at the cost of 有支付的意思吗？嗯，对的。

at the cost of the purchaser------由买方支付谢谢。不客气