The flat-rate handling fee is S$5.99 and it is only applicable to normal samples. For free samples, they are fully paid for and there are no additional charges to deliver the free samples. Handling fee covers the delivery, material, labour and logistics cost to support the sampling service. You can redeem up to 4 different samples in each checkout and it is likely that you will find samples bundle with larger supply (up to 1-week supply) on Samplestore.com.