Depends on how many you get. One unit (depending on what batch you bought/buy) and a power supply with get through at no additional cost. Four units alone will cost. Once you past a certain threshold, $2000 right now IAW https://www.cbp.gov/trade/basic-import-export/internet-purchases you may pay. Here is a quote from the link provided "Pitfalls: If the item's value is more than $2,000, it may be held at the mail facility until you can arrange for a formal entry. This may require either hiring a customs broker to clear your goods or you may file the paperwork yourself." key phrase "may be held". Other important information can be found here as well about commercial purchases having a limit of $2500 before paying duty.