I recently bought a house as is, and the lawn looks like crap. The
previous owner neglected to water it regularly and keep it maintained,
so half of the lawn is pretty much dead/weedy. It's St. Ausgustine
grass.

Any suggestions on how to redo my lawn? I don't have a lot of money,
so I can't hire a contractor or buy a truckload of new St. Ausgustine.
I'm thinking along the line of renting a tiller and reseeding it with
another kind of grass (What kind of grass can coexist with St.
Ausgustine?)... What's the best way to approach this project? I've
asked people at Home Depot and they weren't very helpful.