Peppercorn was indeed costly for centuries, and its trade was highly profitable during the rise of modern Netherlands. The country's Golden Age was built upon the spice trade, and for an individual a sack of the dried kernels was wealth for life.
The word peperduur is probably a cognate of the medieval French expression from which derives the modern "cher comme poivre." French cuisine promoted the use of pepper as a superior ingredient, though the commodity had been valuable since the time of the Roman Empire.
Native to a region of India, the pepper that Europe demanded for cuisine and medicine was available only in meager supply relative to demand ergo expensive.
The value of pepper in European markets attracted all the great shipping powers, from the Romans to the great Italian post-empire cities to the Portuguese (whose Vasco da Gama learned how to sail around Africa) to the English to the Dutch who competed and battled with the Portuguese fleets for primacy in the market for this and other spices in the region.
Pepper was at the center of the great merchant operations of the Dutch East-Indies Company (the V.O.C.,) a military-commercial incorporation that made a tiny country the principal maritime power, and Amsterdam the richest city in Europe.