If you are in Sydney on business, and don't want to stay in the inner city, then the nearby suburb of Glebe is a great option.
The inner city is buzzing through the day, and there's lots to see and do. However, I'm not really keen on accommodation in the inner city. Surprisingly, there is not a lot of action in the actual city after business hours, restaurant wise, at least.
Glebe
Glebe is the best of both worlds, as it's close to the city, but is its own unique precinct. There are a number of motels in the Glebe area. They cater not only to tourists and business people, but also to visitors to the nearby Sydney University. The University Motel, across the road from the University, provides 3 star accommodation for approximately $US 100 per night. From here, it's a five minute stroll to the Glebe Road restaurants.
Restaurants
Just stroll up Glebe Road, and you'll pass Indonesian, Thai, Indian, Vietnamese restaurants and lots more. Of course, as restaurants do, these come and go, but there is plenty of choice. Choosing the restaurant is half the fun, and a walk up and down Glebe Road to choose is part of the experience. Prices are reasonable, and tipping is optional.
Gleebooks
Glebe Road is also home to one of Australia's best independent bookshops - Gleebooks. If one bookshop is not enough, Gleebooks has two - one a specialist children's bookshop, plus their main shop. They are renowned for regular literary events, both free or low cost. Gleebooks has won Australian Bookseller of the Year a number of times.
Allow some time to have a leisurely browse, as it's the sort of bookshop where you are likely to find some real gems, not usually found elsewhere. Of course, they have the latest bestsellers too. With Sydney University nearby, the collection on offer at Gleebooks is broad ranging.
I usually work it into my timetable, so that choosing a restaurant and browsing for books is part of the evening's experience. It's a great place to browse and is open seven days a week, and till late at night.
Bus Service to the City
Bus services to the city are frequent day and night. The trip is about 10 -15 minutes depending on traffic and time of day. You can drive of course, and parking at motels is usually free. However, you will have to pay for parking in the city. Unless you need a car, take the bus. You'll see more, and you won't have to worry about traffic or parking.

