Keep the price slightly lower than the average cost of a full tin of any of the options included in the sample pack (or market average) , and it's a no brainer.
JTS seems to be on the rise. It'd be a smart business move to provide a sample package at a discount.
To quote Rick and Morty; "show me what you got."
Show me quality and consistency and you'll have a customer for life, unless you fall off.