Only suggestion is that save the money for Prague instead of spending it all in Vienna which is easy. Both are beautiful and old cities but Prague is still way cheaper yet you can get the exact same luxury.
The Austrians have some great beers but make sure you taste as many Czech as possible since they are the kings. Talking about beer, do not forget to drink some draft Budweiser in a Prague pub. It has the same name as the one sold in USA but the two company has nothing much in common except the lawsuit over the name. One of THE best draft beer you will ever have in case you like a little stronger beers.
Another thing is that (and I may be wrong as it was like 6+ years ago I have last seen the two countries) the Austrian countryside is real pretty while this has not been the case for the former communist European countries. In most of those it is hardly worth checking out anything else other than the capitols with a handful of exceptions the country sides don’t look too great. I don’t say it is 3rd world like when you see pictures from India or central Asia but just nothing interesting for a tourist IMO.
Ohhhhhh.... I don't know if this applies in your case but the chicks are awesome in Czech, in Slovakia, in Southern Poland (this I can’t confirm but many of my friends told me so), and in Hungary. My theory: The reason for the high amount of drop dead chicks per square kilometers is that just about every soldier of every nation left a little DNA in these countries during the past centuries. If you are alone make sure you get into a few clubs. Believe me you do not want to miss out on a party in a nice club where all the drinks will be on you and at the end of the day you will still have not spent more than $1-200. Just to get an idea in Hungary a beer in a nice place, and I mean nice place, would sell for may be $0.70. The same Fosters for example that you buy for $1.10 in Publix... but pay $8.00 for it in Miami Beach pub and even more in a nice USA club.
Finally if something seems expensive anywhere in Czech than don’t buy it or don't go in there as probably someone is trying to take advantage of the American tourist. Especially taxi drivers or striptease clubs are to be avoided. Getting into a taxi at the airport and confessing that you just came from the states and want to check out some cool places is not the way to start. This does not really go for Austria though.
Have fun.