Tax and customs clearance cost vary from one country to country.
For most countries, it's easy to import products, but if you country has a restrictive import policy, then you are responsible for finding out the situation in your own country before placing a big order on Naughty-naughty.
Every country has a tax threshold, if the total amount of your order is below the threshold, then no need to taxes. For general customers, you don't need to worry about paying taxes for too much, because the total amount of your older will be most likely below the tax threshold of your country.
For retailers, you'd better research for how much is the tax threshold and how to calculate import taxes before you import large quantities of our products to your country. The bright side is that in many countries the importing tax can be deducted when you start to sell the products.
Tax is charge based on the total amount on the invoice, contact us if you need help of putting a small amount on invoice, we may be able to provide some help in some cases.