If the quantity is small and they are in stock, samples will be free, customers only need to pay the express fee.
If the quantity is a little much and they are in stock,It needs customers to buy them and some of samples costs can be returned back through next batches orders.
if the quantity is more or less and they are not in stock,We would like to produce samples for customers specially if customers agree to pay the samples costs,Some of samples costs also can be returned back through next batches orders with a certain term.