The duty threshold in the EU is 150 EUR.

The D&T rate will be determined by several parameters like outbound, destination, HS code (product classification), product origin country, value, and more.

For the USA there is a threshold above 800$, and also US Sales Tax, that varies on the state. US Sales Tax is collected since January 1st, 2020  following a supreme court decision in 2018 that rules that remote sellers with no physical presence in a state must collect and remit the sales tax for each state where they do business which applies also for cross-border sales into the US market.  The tax is different for each state.