Not sure if this is already reported.

repro:
1) Get a character with 7lb, or other way to reduce move cost.
2) enable auto-pickup.
3) set :t to display energy cost
4) Move over object to pick it up.
Bug: energy cost is 2 * move cost.
Expected: energy cost is 1000 + move cost, as if you did the two actions together.

In the extreme case, (leveled beastfighter with blessed 7lb and 950 base move cost) move and pickup costs 809 energy, less than dong pickup alone.

It appears to be the real energy cost, as monsters behave as if they had a small time-slice.

addendum:
missile reload also behaves similar.
Manual reload cost 1000.
answering Y to a new ammo set the general cost to 2 * fire energy use.