I measured the toggle costs for focused fighting, focused senses, stealth, and combat jumping some time ago, by running end to zero, then turning one toggle on and timing how long it took to regen to 100 end.
Focused fighting, senses, and stealth all worked out to 0.333 end/sec.
Combat jumping seemed to take 0 end per second. Others have said that it's actually like 0.0375 end/sec. Either way, it's a very low number.