The problem with importing goods is that there is often no clear definition of whether certain goods is taxable, or tax exempt. Especially something that falls near/on the middle ground. Similarly is the case with TV vs Monitor, ATSC tuner vs no ATSC tuner. I bet some of the customs don't even know wth is an ATSC tuner, and the argument may actually sound illogical. However, with regards to TV vs Monitor regarding ATSC tuner, you can actually try to google out the industry standards and print it our as proof before sending the item back home.
But of course, declaring the item as personal effects is the most trouble free way of bringing things back to Msia. However, the items need to be certain age old before they could be declared as personal effects. Specific duration could be found online or just call up the customs office. You can even bring a vehicle home under personal effects and save up the 300% tax/duty....as long as u pay for the freight

When unsure of the situation, I like to use fedex/ups express, brokerage is covered and they expedite customs inspection procedure. Therefore, sometimes you can actually get away with items that are suposedly taxable without actually paying the taxes.
I believe they actually have "specific" customs checking these courier's goods instead of passing the items to the more general customs (those that inspect goods for local post services). Just like they have their own jets for transporting overnight shipments. Not to mention that you get your stuff within 3 business days at most with these services....the extra cost is something you've gotta bear of course.
The government of Canada taxes all imported goods over 20CAD and items declared as gift at 60CAD or more. One trick that I've found to be very effective in discouraging the customs to open the item for inspection is to get the seller (usually my friend forwards the stuff to me from the states) to tape the package thoroughly with cellotape. Customs usually would just let the item pass through the x-ray and forget about opening it.

Otherwise, some customs would neglect the declared value on the declaration form and imply proper taxes on the actual invoice included in the item if they do open up the item and found discrepancies on the item's value. (yes, I've kena once before because I forgot to ask the seller to remove the invoice)

I do not condone tax evasion though!

it is illegal