travel Gunma

any one know a cheap way to get to the Gunma prefecture?

Depends on where in Gunma you want to go!

The Takasaki/Maebashi region is most easily (and relatively cheaply) accessed by the JR Takasaki Line. The Isesaki/Ota region by Tobu Isesaki Line.

There are also direct highway buses going to hot spring resorts such as Ikaho and Kusatsu, which are relatively inexpensive.

whoops i forgot to ask if anyone knows a cheap or inexpensive way to get to gunma from osaka

There is a direct overnight bus between Gunma and Osaka, stopping in Numata, Shibukawa, Maebashi and Takasaki before going to Osaka OCT (also stopping in Kyoto along the way). The one way fare is around 9,000 to 10,000 yen.

You could also go from Gunma to Tokyo, from where competition has created even cheaper high way bus fares. Check out 123 Bus, for example:
http://www.123bus.net/index.html