These traditional varieties of small grain rice, mysteriously, can only be cultivated once a year during the rainy season with a growing period of six months (October - April). Even with the climate change and unpredictable weather conditions that we are currently experiencing (blessed with abundance of rain on supposedly dry months), growing them off season will produce very little crop...if any. Hence, their seasonality and high demand makes it rather pricey; $12 se-gantang (3.5 kilos) freshly milled, compared to the subsidised supermarket price of $10-$11 per 10 kilos for Thai fragrant rice (baras tempatan $13.50/10kg sack).
Baras Brunei is an acquired taste. This is because the rice grain is small and some varieties are sticky compared to the imported Thai rice varieties. In the olden days when meals weren't as lavishly diverse as today's, Baras Brunei or Baras Kabun were simply eaten with dried salted fish or ikan masin. This was the staple food of many people in the olden days but probably a delicacy to many today (albeit served with other dishes). Some like it and others don't, and some even swear by its therapeutic properties. There was a story about a Singaporean who suffers from the 'popular' modern diseases; hypertension, diabetes etc. He came for a visit to Brunei and during his lengthy stay he acquired the taste for baras Pusu. Long story short with Allah SWT's will, his ailments receded and he's been 'importing' baras Brunei to Singapore eversince. Wallahua'lam Bissawab.
Theoretically, freshly harvested and milled rice is nutritionally better than rice that have been subjected to post-harvest processes required for export and the constant periodical pesticide fumigation while being kept in storage.