Tax + Avoidance isn't something we offer I'm afraid
As you've mentioned, there are ways that international customers can lower
their import tax bill e.g. making multiple small purchases which are under the import taxable threshold, however this obviously depends on your region, and the rules, regulations and laws surrounding it.
If you contact us, under the "Delivery Questions" form, we can look at your specific case.https://www.modmypi.com/contact-us