since after是什么使用方法

Economyis one powerful motive for camping, since after the initial outlay uponequipment, or through hiring it, the total expense can be far less than thecosplayt of hotels.

请问为何两个since after 连在一块用啊？

Economy is one powerful motive for camping, since after the initial outlay upon equipment, or through hiringit, the total expense can be far less than the cosplayt of hotels.

网友句子中的 since 是连词（不是介词），用于表缘由；它后面的 after 才是介词。

句意：图省钱是露营的一个主要动机，由于在开始时购买或租借露装备之后，其总成本要比住旅馆开支少不少。