Chinese Wholesaler / Dropshipper question

Just a quick question when it comes to the Chinese wholesalers and dropshippers; I'm in the U.S. and I'm curious as to the customs and duty fees for importing some of the items from these dropshippers. I've had to export a few things to Canada over the years for my business and it has been a major headache at times with declaring a value, paying duty taxes, etc.

If I buy something from say Pandawill, and I ask them to ship it to me via UPS, how does the duties and taxes work?

I have no experience from Pandawii (I use dhgate.com)

In my country (The Netherlands) I have to pay taxes over all products worth more then 21 euro (25usd?)

Chinese wholesalers know this and always label the package as 'Gift' and put a low value on the package. Luckily customs havent open my packages.

I ordered many games and they did it like this:

10 Gameboy games = 10 x Plastic Game Card + Paper Box (Gift) 20 usd
10 Gameboy games = AC Adapter with plastic box (Gift) 20 usd

I do not know about taxes in USA but I hope my example give you an idea how this thing works