Above write-up (republished by TG) obliges one to give it a second but fresh look on one area propping up, though not seemingly thought of. That has something to do with the conflicting philosophy, rules and regulations independently framed/enacted and sought to be implemented and enforced by the two concerned regimes namely, 
income taxation and customs duty. 

The multitude of material available in public domain might suffice for anyone interested to embark on a lifelong research on the subject area; albeit turnout to be an inconclusive one.

The following abstract from one such source may help in having a glimpse of it: 

Q
For multinational companies, dealing with either tax authorities or customs administrations can be a major headache. So how about serving two masters at the same time? Surely it would not be easy. In the cross-border business environment, it is not uncommon to see multinational companies struggling with the conflicting demands from tax authorities and customs administrations. Indeed, the conflict between transfer pricing and customs valuation is attracting attention from various stakeholders, including tax practitioners in the game. The solution to this conflict varies with countries.
UQ
It seems, therefore, that any discussion or deliberation, more so any policy or enactment,  exclusively on the subject of ‘transfer pricing’, as divorced from customs duty implications, is unlikely to serve a useful purpose; instead, might eventually turn out to be incomplete and ineffective in every sense, thereby perpetuating the largely obtaining conflict .