I'm going to Frankfurt next week and have a few days to wander on my own. I was thinking of going to Prague (Aushwitz), Vienna and Munich before going back to Frankfiurt. I'm a 30 yr girl on a serious budget. Suggestions on where to stay in each place, what else to see in these cities if I only have 24 hours in each (relatively). Thanks!

You want to spend 24 hrs in each city? How are you going to travel between the 4 cities? On a serious budget?

Why not just travel around the Frankfurt area for a few days - like the Rhine/Mosel area. It'll be a lot cheaper for transportation and you'll actually get to see something instead of spending your time in either trains or planes.

I was thinking that too - since time is short and the budget is tight, you might do better to focus on areas closer to Frankfurt - or - choose 1 of the 3 you are currently thinking of and spend you time in and around that area. That way you can see more and spend less getting from place to place.

I've only been to Munich, of the places you mentioned, but I really enjoyed it and definitely recommend it.

For Auschwitz, you're better off going to Krakow than Prague.

Given the travel time involved, I am not sure how 24 hours in each city could be accomplished.

This reads to me like another request by a person who needs to do his or her homework before asking us to plan the trip.

Unless flying, the trip between Vienna and Frankfurt is going to take 7 hours, 17 minutes each way, shortest time. The round trip train cost is €112.40,

Given the constraints, and a choice of 3 cities, I say limit your visit to 1.
And that one is: Vienna.

There is more to see and do there.

Second choice: Munich.

I am ruling out Prague for one reason: cost. The cheapest round trip traub ticket from Frankfurt to Prague is €132.60 or about $180.

If departing from Stuttgart, a flight with German Wings to Vienna is feasible but more expensive and it involves getting to the airport in Stuttgart.

Air Berlin was not much help for Vienna or Prague.

Munich Frankfurt by rail would require a complex use of Länderkarte to make cheap trip.

If memory serves me correctly, it would be possible to travel from Frankfurt to Aschffenburg, which is in Bavaria, and continue from Aschaffenburg to Munich on a Bayernkarte.

Travel times are restricted, but the cost would be a lot less.

Another Bayernkarte the following day would be used to travel between Munich and Salzburg.

The problem is that there are not many local trains on the route so travel times would be very limited.

If the budget is tight, which is how I interpret "serious", local travel within the Frankfurt area might be more feasible.