The EU price includes the tax as well. This is the case with everything in the EU, not just laptops. I'm pretty sure the US price 899 is without any taxes as those are different from state to state, so the final price is more or less the same.
The Vivobook S 15 OLED was one of the first notebooks with the new Snapdragon X Elite, and now Asus is also launching a cheaper version with the new Snapdragon X Plus 8-core. However, the remaining specifications, including the 120 Hz OLED, are identical. However, the price difference to the faster X Elite model is too small.