The value is unimportant for the tariff.
tariffs goal is to spur consumption of domestic produced goods. The higher the tariff the more effective it is at doing this. Some countries create their own unique technological standards, exclude and demonize foreigners and goods or start and lose wars in order to build or invigorate domestic industry and consumption. Those methods are also very effective.
tarriff is based on the value of the underlying product unless you make the tariff prohibitively high and ban the use of the underlying product