"and most exporters, especially in Asia ,are aware of that fact and provide just that :) " - While many and maybe even most Asian suppliers are honest and provide accurate commerical invoices, I meant this as a warning. We help many people get started importing goods from China and one of the most important points we make is to negotiate on product price seperately from freight otherwise you have no idea what you are really paying for, let alone the taxable value situation. We see it very frequently that the maker of goods in China will be in an alliance with a relative at a shipping company and try to make extra profit off of the small unsophisticated buyers. So they will quote very low shipping prices, but they jack up the product price to compensate, which creates two problems, 1) they make more money than their competitor who just quotes FOB or EXW terms, AND 2) you have a higher taxable value than you would with their competitor.
So, ujeans, just make sure you have a reputabe supplier, and good clean commercial invoices. I recommend that you establish a relationship with a customs broker locally so they can help protect you from potential errors, deliberate or accidental, also if importing regularly you need to establish a "continous bond" which will save you money. FedEx/UPS etc are known to make errors and misclassifications, primarily just due to their high volumes and electronic processing, they are cheap, so you will need to weigh the cost/risk here. Get educated on how GST and Customs works, or have an employee learn becuase you need to watch these things. In todays competitive market profits and can be made and lost by harmonized tarriff codes, especially in finished clothing related commodities.