For 2400 square feet, it's gonna cost you.
FWIW, I got 450 square feet at the Grass Outlet.. installed it myself. The grass itself was $160/pallet. But, it requires much less water, etc.
You can probably get bermuda, zoysia, or st. augustine cheaper. Buffalo grass does well when you water it less.. does not do well when you water it more.
If I could do it over again (and was actually not closing on the sell of my house in 3 weeks), I'd go with Zoysia.
I'm not aware of anyone who does grass installation, but I'm sure they are out there.