That makes sense for import charges but seems a little unfair for shipping. If I buy a pair of SB13PFCs or SB26STACs from Madisound I will not reach the threshold to get free shipping but won’t have to include the shipping in driver costs. If I buy a pair of SB26STCs from THLP (which are NOT available in the US) I have to include the shipping in my driver costs.
(The SB26STC (about EUR 15) is the equivalent to the SB26STAC (USD 52) but have a plastic faceplate. Used in a 3D printed waveguide, the $37 aluminum faceplate of the SB26STAC simply gets thrown away.)