Does studio mean that you have your own toilet and kitchen?

Studio has all the facilities of a one-bedroom apartment, without the actual bedroom. Great option for students, heavy travellers looking for a pied-a-terre, etc.

Yes, studio is a separate unit/apartment. It's just that it has one room, plus bathroom/toilet, plus a kitchen that can be open plan in a room, or a separate. It does not have a separate room for a bedroom. But sometimes they have a loft bedroom. Typical studio would be smaller and cheaper then 1 bedroom units (but some are extra large, designed, have view - the price is much higher for those).

I believe basic studios on Sydney outskirts - Chippendale, Surry Hills, Potts Point are going for arround $300 unfurnished. Studios in a city - from $400.

Accomodation without individual kitchen and bathroom is ussualy in a share accomodations - when a larger residence is rented to few tenants per bedroom. And kitchen / Living room / Bathroom becomes a comon areas shared by all tenants. Some larger rooms might have own bathroom and/or Walk-In-Robe. But that are more expensive. Ussuay friends pool together to rent a larger residence to share, or some websites have listings for those.