This is a large home and with two A/C units, I would assume that during the summer months you could expect $300 - $400/month, but you will see a big improvement during our winter months, allowing you some relief.
It looks as though this home is sold, so if you are looking for something similar, feel free to contact me.
Thanks so much,
Sarah Garrett, Realtor
ALLIANCE REALTY GROUP
"Chosen Best in Client Satisfaction 2006-2012" by Gulfshore Life Magazine