If seller is willing only way to drop cost of customs is to have the shipper mark it as broken/faulty. Will absolutely not work at all times.
Edit: or go in person or have someone who is traveling from seller’s country to yours bring it and not declare on customs forms. Also not 100% effective. This is also known as smuggling. For small personal tech items, almost certainly no major repercussions or difficulty. Your milage may vary.
Pay wall