Visiting Germany in less than a month--help with trains please

First thing, don't get a pass, at least not right now. There are cheap ways to travel with out them. You can go all over Bavaria for 23 euro all day for 23 euro/day and you just buy the day of travel. On weekends, hubby comes along and its 27 euro/day. When just going in the Munich area you can get a day pass, or buy a monthly local pass. You don't say how long you are there. There are other longer term deals, like yearly half fare cards. So there is no rush. Just research now. The important questions are, how long are you there and where do you want to go.

We're only there for two weeks. He will be working during one of those weeks. We are renting a car for three days before his work week starts and haven't decided what to do those last few days after his work week.

Kaufbeuren is 1 hour by train from Munich, most are direct, a few with a single change at Buchloe. On week days, travel after 9 am on a single Bayern Ticket for 23 euro by yourself. That covers into Munich and back and all the subways, buses, s-bahns in Munich and suburbs. On weekends, you can travel anytime and 27 euros covers both of you. You might want to use the car for places that are hard to get to by train. Fuessen (Neuschwanstein) is just 30 miles south, over to Austria (get a vignette), Schongau (car can take a short cut), Oberammergau. In 2 weeks you can see and do a lot and never leave Bavaria/Austria. Don't forget, hubby will be picking up tips from locals while he is at work.
http://www.bahn.com/i/view/USA/en/prices/germany-regional/bavaria-ticket.shtml

There are a lot of thing you can see from Kaufbeuren without going to Munich.

Kaufbeuren has some of the medieval wall still in place,

Take the train up to Ulm and climb the highest Gothic church tower in the World,

Take the train down to the island city of Lindau,

Take the train down to Oberstdorf, in the Alps. Take the bus from there up the Austrian Kleinwalsertal,

Take a train to Füssen and the castles,

And of course, go into Munich (there is a lot to see there),

Or go to Memmingenberg, and see the RyanAir passenger trying to figure out why they are not in Munich.

All those trips can be done with a Bayern-Ticket for less than a day of a railpass.

After your husband's work, when you have more time, make a day(s) trip through Munich to Berchtesgaden. From Berchtesgaden, you can see Hitler's Eagles Nest, cruise the Königssee, or take a day trip to Salzburg. Or take the train to Kempten and follow the Ausserfernpass rail line through the Tirol past the Zugspitze to Garmisch-Partenkirchen. From there you can go to Mittenwald or all the way to Innsbruck (or even over Brenner Pass to Italy).

If you take some time to learn the rail system, you don't need a car. Here is a map of the rail network in Bavaria. I've spent weeks touring this area without using a car, and saved hundreds of $$ in the process.

Thank you Sam and Lee for the information. Lee, thank you for the notes about visiting around Kaufbeuren!

So if I buy a regional pass, do I need to buy it in advance? Is it the same price if we wait until we get there?

If by "regional pass" you mean a Bayern Ticket, these are always the same price. You buy it from a machine in the station on the day of travel. Or you can buy it from a ticket window for a slight surcharge. If you're buying it ahead, note that you have to be careful to specify the date of travel (the default is for travel on the day of purchase).

The Bayern-Ticket is the same price whether you buy it in advance or on the day of travel. There is an additional 2€ charge, however, if you buy it from a clerk at the DB Travel Center instead of from a machine.

(Edit: Oops - Harold beat me to the answer while I was double-checking the surcharge!)

OK thanks everyone! The Bayern ticket sounds like the way to go! :)

The fabulous island garden paradise of Mainau Island is also within Bavaria - just. I think that you can get there without crossing into Baden-Württemberg on the way. We loved the gardens there.

Mainau is quite a ways into Baden-Württemberg, about 2 hrs, the last 10 minutes by boat. But on a weekend you can use a Schönes-Wochenende-Ticket, an all-day pass like the Bayern-Ticket, but for all of Germany (regional trains), for 44€ for both of you (up to 5, actually).

On a weekday, you could use the similar Quer-durchs-Land-Ticket, 52€ for two. There might also be a boat from Lindau (to which you could go using the Bayern-Ticket) to Mainau, but it would cost more and take a lot longer.