Barton Park driving range is a great little spot 15 minutes south of the Sydney CBD. It's quiet, cheap, and one of the rare driving ranges in Sydney that let you hit off grass. You can take your own clubs, or they have some there to hire. You can also book in for a lesson with the resident pro if your swing needs some polish. There's also undercover areas if you want to have a hit in the rain.
Barton Park Driving Range is open 7 days a week from 8am to 6:30pm in Summer and 8am to 5pm in Winter.
It's about $15 for a large bucket of balls and $11 for a small bucket. Barton Park's phone number is (02) 9567 7234 if you have any questions for them.