The tax and duties would be the same whether it's DHL or a customs officer, the only thing is that customs officers generally charge a lesser handling fee, if at all. And sometimes they let a package go through without any charges since they're lazy, like what happened to me
There's nothing dishonest about what DHL is doing. You are by law required to declare and pay taxes and duties on stuff you import. DHL does that for you and carries out the law diligently as it is in their financial interest in doing so, since they can charge service fees.
You're lucky if you only had to pay 15 USD. Here in Europe I would have ended up paying over 60 USD in VAT alone, plus several points in duties. Plus probably around 30 USD in DHL service fees. So that's a good 100 USD or 30%+ on top of the already hefty price tag.
I am in Europe, Denmark. Thats why i think 15 usd i way to less, but i do not complain . But fair, i think you know more about this than i do .