Only 80? That's nothing. I keep mine between 83 and 85 during the day....and hibernate in the master bedroom where the big tv, computer and window AC is. I do the same in winter, keeping the rest of the house pretty chilly, but use a portable heater. Otherwise, my electric bills would hover around $250-300/month.
I live in Tampa, where it is in the mid to low 90s most days, and my house has no shade. I keep my house around 78. I pay about $60/mon for AC. I used to pay a LOT more, but then I spent a few hundred dollars adding way too much insulation to my attic.
Also, when I had to replace my AC, I went with a two compressor unit. One is sized for the house, one is half power. When it fires up, it starts with the half power unit. If that can keep the house cool, it continues on half power. That doesn't really save any money, since it basically has to run twice as long, but the longer it runs the longer it is taking humidity out of the house.