For rental BELOW $3,500 monthly:
The tenant in this case would be expected to pay a commission to the their own agent. However, the agent would be representing you and getting all the relevant grounds covered before you go ahead to sign any paperwork.
2 years lease: 1 month rental
1 year lease: 1/2 month rental
For rental ABOVE $3,500 monthly:
The landlord would be covering the commission for both the landlord and the tenant agent. So tenants won't have to worry about any extra cost, regardless of whether they have an agent or otherwise.
2 years lease: 1 month rental
1 year lease: 1/2 month rental
The landlord agent would be expected to split the rental commission with the tenant agent.
Regardless, it would be more ideal to engage an agent due to the complicated paperwork and to ensure a seamless transaction. Furthermore, engaging an agent would allow someone professional to act in your interest should any issues arises.
For example:
a couple rented a place for $2300 monthly, and decided to not engage an tenant agent in the hopes of saving commission.
Without Agent:
a year lease: $27,600
total: $27,600
and say that say should they have engaged an agent and the agent manage to negotiate and get a seemingly decent $100 discount monthly
With a Tenant Agent
a year lease:
total rental: $2200 x 12 months = $26,400
commission + gst: $1100 + 7% = $1177
total: $27,577
Even though the savings is minimal or, do also note that having an agent would meant someone helping you filter through the listings, making arrangements, and covering all the required admin and site work to guarantee that everything goes smoothly. So consider this a discount with lesser work.
A lot of tenants still prefers to do it themselves, but I'd still say it's nevertheless harmless to get an agent to act on your behalf as the time and money saved justifies the value much better than going through with it yourself.