I don't think this is correct.
A while ago I actually went through the trouble to find out, and the rate for FP was (if I recall correctly) 3.25% if above $800.
I don't know the rate for ink, but I do know that FPs are taxable (as they should) if you go above the limit.
Incidentally, one of the vendors mentioned above recently (2 months ago) made a mistake and declared the wrong price on a FP I bought (they forgot to take out the discount), and it amounted to $2 more than the limit. DHL charged me 5.4% on the entire purchase + $15 of "convenience" fee. There is no arguing with DHL, so the vendor gave me the amount back in store credit (already have another pen on order ).
HS Code 9608.30.11, go to "Harmonized Tariff Schedule": https://hts.usitc.gov/current
Go to chapter 96 Miscellaneous manufactured articles: EU and most WTO trade partners are under "Generalized System of Preferences", A, that' zero.