I've grown pot for almost 30 years and I know what it costs to grow a pound of bud....
Here is exactly what it costs me.... Per 60 day flowering....
Nutes and mollassis- 30 dollars a grow
Power- 30 bucks per month per 600 watt light- 120 dollars per 2 months- 12 on, 12 off
Monthly upgrades? 6,000 a year? Whatever...
Clones- Free. 20 dollars a month to care for mothers....
Time- maybe an average of a half hour a day on a 2 pound grow.
With a pair of 600's and a 6 by 6 foot room I get a little over 2 pounds of of dry bud off 12plants. At the very most, I incur about two hundred dollars in expenses and use about 24 hrs of my own time. One hundred dollars, set aside per grow, easily covers new lights/bulbs/.....
That adds up to 125 dollars per pound. I don't count the labor because the 1/2 per day is one of my most enjoyable times of the day.....
There's quite a difference between 250 per grow for me and 4800 for you....
Well our gardens are different scales, but 6K a year is easy on repairs/upgrades, as every year I have to:
Replace 8 1KW bulbs twice ($1900)
Replace 1 window AC a year (they just burn up) ($500)
A couple water pumps ($100)
1-2 new CAN150s ($200 each)
etc etc