The value was low enough not to be taxed. Your DTV doesn’t grant you any duty exemption benefits, just like most visas, including non-immigrant visas. You can’t simply decide to bring a container or large boxes and expect to be tax-exempt. Feel free to check customs laws...
You can't get duty exemptions on a DTV. Exemption is only in one very specific case with strict conditions when holding a work permit. You may get lucky on low value shipments but it's not a rule... Feel free to search other expats groups and see how risky and expensive it could be.