Is $1,600 to install attic insulation a fair price?

I live in Savannah, where it's very hot in the summer. My house, built in the 1950s, has zero insulation, and it's difficult to keep cool; it stays around 76 degrees Fahrenheit regardless of settings. I'm hoping this insulation will help bring the temperature down to around 72 degrees. My energy bills are significantly higher in the summer (around $350) compared to winter ($75-90), despite having gas heating. I'm also looking into a contractor that participates in a rebate program for this type of work. I was hoping for a cost closer to $1,000 and am wondering if this quote is a decent deal.