In junior roles, I was getting $40-45k. In intermediate roles, I'd expect $55-80k.
$80k for someone with 5 years experience is possible, depending on how big the studio is and how you negotiate. I've seen situations where people of equal skill/experience/value have $30k difference in their salaries, because one gave a small number in their interview and didn't negotiate, while the other demanded a high number and rejected counter-offers :/
I can't tell you how much senior staff can get paid, because I quit after about 6 years experience to start my own company 
$80k before tax is about $62k after tax, plus an extra $7,200 paid into your compulsory superannuation account (accessible at retirement, or when you leave the country if not a citizen).
The Aussie dollar is generally worth pretty much the same as the US dollar lately, so if you're buying stuff from US stores yourself, the cost is still about the same, except with shipping added on top. Many imported products (not grey market / ebay self imports) have artificially inflated prices though. Anything Apple, they double or triple the price here. A game that's $60 on the shelf in the US will be $120 on the shelf here. Expensive software, like Autodesk products will also mysteriously double in price... 
I live the Melbourne outer suburbs at the moment, a 25 minute drive from the city, or 40 mins on the train. Three bedrooms, a back yard, car-port, dishwasher, central heating and AC is around $15k a year in rent
Before that I lived in the inner suburbs, a 10 minute train or 15 minute tram ride from the city, and had no need for a car. Two bedrooms, no heating or dishwasher, outdoor off-street secure parking was around $20k a year in rent. There was no AC either, so I bought a portable one for a few hundred, which I'd only use for about one month a year (when you get those 40ºC+ / 100ºF+ days).
I did have a room-mate in that house, but when he moved out, I decided to live alone instead of seeking another one, and I was still ok financially -- I just couldn't go out 4 times a week any more
I also rent a tiny office in the Melbourne CBD for about $7,500 per year, which is incredibly cheap.
Even when I was earning $55k (before tax) and paying $20k rent, I was still managing to put away a few thousand a year into a savings account somehow...
As for international travel, the Americas and Europe are very expensive to travel to, but New Zealand is very cheap, and south-east asia can also be pretty cheap to get to sometimes - Thailand, Vietnam, China, Japan, Fiji, etc... The stereotypical holiday destination is Bali, an island in Indonesia, which costs about $250 to fly to.
Not sure what the custom is in the USA -- I had some European friends who were surprised that their new apartments didn't come with a refrigerator -- they assumed that would be supplied by the landlord. Fridges and washing machines are the tenant's responsibility -- except in apartment blocks that specify a "shared laundry". Occasionally I've had apartments that have had a wall-mounted clothes drier, above the spot where your own washing machine goes, but that's it.
Utilities are also generally the tenant's responsibility -- no inclusion of electricity/etc in your rent.
Side note: When I was renting in NSW, I'd never heard of a "water bill" -- this utility in particular was always paid by the landlord through property taxes/rates, but since moving to Vic I've been paying water/sewerage bills as well (not much, about $20 a month).
Some utilities are quite expensive here. Electricity has been going up and up due to stupid government investment / beuracracy
gold plating is the excessive expenditure by electricity networks on poles and wires to increase their revenue (under the National Electricity Market regulatory framework, the more the power companies spend, the more they get paid – and this spending constitutes the single biggest component of the rise in our power bills)
I've gotten bills of $260 a month before during winter, when using power-hungry heaters all day long, and I wouldn't be surprised at a $100/month electricity bill.
Public transport depends on which city you want to move to and which suburbs. In Sydney, I got so fed up with transport that I decided to rent an apartment within walking distance of my job
When moving to inner Melbourne though, I fell in love with the tram network.
I rely on the public health system, and don't worry at all about not having insurance. It's not like the US where you need insurance. e.g. I can go to the doctor around the corner from me and just give them my Medicare number instead of paying, and they bill the government instead of me. If I have to go to a private doctor, I can take the bill to a Medicare office and have some percentage of it reimbursed to me.
I'm not sure though if an American on a Visa has access to our public health system -- you'll probably have to pay your own way unless/until you gain permanent residency, and then you'd be able to get a Medicare card.
Even then though, the cost of private health insurance here is much cheaper than in the states. When I did have it, I was paying about $60 per month for me and my girlfriend.
From what I gather, the biggest shocks to you will be the price of food (both ingredients and restaurants) and alcohol (both at liquor stores and bars).
