So that 400W charger costs $240 = 60¢/W

Kinda pricey for the rated output...BUT... when you consider that it already includes a built in supply and runs directly off AC in the first place, that makes things a lot easier for folks who might not have a supply yet.

Also keep in mind that charger inefficiency is calculated at 25%, so if it were a DC-only charger then 400W + 25% = 500W supply... however that charger already includes a supply with it