SkyBus to CBD has a special at the moment. Melbourne Express $15 (usually $19.75) but if you don't mind around 20 minutes extra travel time use public transport for $4.50/$2.25 Concession - 901 bus drops you at Broadmeadows Station (Craigieburn Line - Platform 1 to City).
If you are a Senior (over 60 years) and travelling on the weekend, all public transport is FREE.
To find the 901 bus stop:
Head past Terminal 4 multi-storey carpark, ground floor. Walk past Hanna's Cafe to Bus Bay 17 for 901 Bus.
https://www.ptv.vic.gov.au/journey
https://moovitapp.com/melbourne-2803/lines/901/695069/4513783/en-gb?customerId=4908&ref=2&poiType=DeletedPage
