i just got my bill in the mail myself, it has gone up about $55 running a 600 some t-5s and the fans. i had thought it may be worse myself while at the same time wishing it were better. i have friends with double my bill with no grow just addicted to leaving everything running in the house so i guess it's no worry. the difference between running the 250 for 18hrs or 400 for 12hrs should be almost unnoticeable only slightly more for the 400 x 12hrs. I'm curious how well you will do with the 400 for harvest. i had wanted to buy a 400watt myself and somehow got talked into buying the 600watt. i can't go to the grow store with a wad of cash i always come home with things i wish i had better researched.
how funny your neighbor thinks there is a skunk near. is there a noticeable difference with the ona? i had heard keeping a fan moving on it makes it work better like you are doing, that's something i did not try.