Once you arrive Tullamarine Airport, you have many choices to arrange an airport transfer to your hotel.
Hotel Airport Transfer. Check with the hotel where you booked your room with if they have a special discount for an airport transfer for you. Somehotels combined this service into the hotel room rate that they already charged you. So, you might be able to get it for free. Always check and ask!
SkyBus. You can easily buy a ticket (using credit card) from the vending machine located at the SkyBus station and get on the SkyBus from there. SkyBus departs from airport to the City of Melbourne every 10 mins (24/7). You can also pay cash (Australian Dollars) and buy ticket directly from the driver as well. Check SkyBus fares click here.
Taxi. If you travel in a group of 4 to 5 people, maybe it is cheaper and more convenience to take the taxi straight from airport to your hotel.
Friends. Do you have friends who live in Melbourne? Sure if you do, tell them to pick you up! That is what friends are for!