aminet's answer is not correct.

As long as the CIF (Cost + Insurance + Freight) value remains under QAR 3000, there is no customs duty charged. For CIF value QAR 3000 and above, Qatar Customs charges 5% import duty + bayan charges (QAR 10) and any other fee your courier may charge you for processing (QAR 100-150).

Please note that this is true only for personal shipments. If the shipment is commercial in nature (or even if you ship it to your work address and mention your company name within the address field, they're probably going to treat it as a commercial shipment), then you get charged customs duty regardless (from my experience).

Hope that helps.

Source: Been shipping all sorts of stuff from car parts to laptops for a few years.