What do you think transfer pricing is, declaring a value for customs for the item being transferred. This is a dispute over the declared value of the import which is which is subject to interpretation using different metrices. Disputes arise because it is in a company's best interest to minimize taxes. Putting a lower valuation based upon a methodology the government rejects is why there are courts, not prison.

I buy a used vehicle for $400 believing it is worth @$1,000. I use the $400 for import purposes as is my right. The government assesses me and charges tax based upon $1,000. I can appeal to the courts if I disagree. I do not, however, go to jail because the government says that since I believed the value of the vehicle was $1,000, I should have used this higher number and by using $400, I committed a fraud. That is the difference.