Would like to make a trip there next year. Would be flying from the states. Can any locals give me an idea of cost to be there for a week or so and attend some matches?
Depends how you go about it. If you're eating out it can cost $20-$30 per meal, at the tennis itself a ground pass gets you to all outside courts. Food and drink are very pricey and fairly limited in choice, I'd suggest trying to eat before and after you go if you want bang for your buck.
It would have been a nice cheap trip back in the day for Yanks. The exchange rate is brutal for you guys now and the cost of living here is stupid.
The tennis tickets are priced more than reasonable, it's everything else that adds up. Aus Open is smack bang in the middle of school holidays which would make accommodation a bit of an issue I reckon, you'd need to book a long way out and it'd be costly.
My best advice would be to buy ground passes. You can even buy them in bulk at a discount and they give you access to every court other than Rod Laver and Hisense. Can't remember if I posted pics or not but when I went last Saturday it was the most people at any Slam on one day ever - 80k. But the matches on RL were such duds that I went cruising to the outside courts. I got a 6th row seat with no effort on the baseline and watched Gasquet/Dodig (awesome match), Stosur/Goerges lose in the doubles (great match too although I was the only one cheering against them), and Raonic win (woohoo). Ground pass would've cost $50 because it was a Saturday I think. During the week it's around $30 I think, cheaper if you buy it in chunks. My RL ticket would've been $150+ if I had paid for it and the matches during the day were duds. Big favourites smoking people. Buy ground passes in a package and if you find out your favourite player is on RL or Hisense in what you think will be an awesome match the next day then worry about getting tickets. If not, sitting in the courtyard is just as awesome. But during the first week especially, ground passes are the way to go and you'll save so much cash!!
Come down here... you won't regret it for a second but bring a decent amount of spending money. As Cessation said, Australia isn't cheap so be prepared! On the flipside, I stayed in the same hotel as Serena and Venus last wknd and my room was $170 per night in a super swank place and only booked it a few days before. But the prices of things will probably be a bit of surprise - especially food and drink even outside the tennis - so just give yourself a bit of a cushion so you're not stressed out about it.