Do you have to pay that percent after item's value will be higher than 500$ (for example) or you have to pay 30-40% in any way even if item worths 20$?
If I buy anything from Amazon, the tax varies and it is very much weird to figure out how they calculate the tax. I'll show some images from Amazon so that you can see for yourself.
However if I directly import goods not from Amazon, then I believe the percentage is atleast 20%,after all those rich bastards won't let me live until they took their share of money from me in the name of import duty.