Kautilya's Arthashastra 2.16.18

2.16.18

paraviṣaye tu - paṇyapratipaṇyayor arghaṃ mūlyaṃ cāgamayya śulkavartanyātivāhikagulmataradeyabhaktabhāgavyaya.śuddham udayaṃ paśyet //

As regards the sale of the king's merchandise in foreign countries:---

Having ascertained the value of local produce as compared with that of foreign produce that can be obtained in barter, the superintendent will find out (by calculation) whether there is any margin left for profit after meeting the payments (to the foreign king) such as the toll (sulka), road-cess (vartaní), conveyance-cess (átiváhika), tax payable at military stations (gulmadeya), ferry-charges (taradeya), subsistence to the merchant and his followers (bhakta), and the portion of merchandise payable to the foreign king (bhága).