This is what I am hoping for in terms of off-road. UK style grass track
Jumps can be made out of wood, drainage pipe is cheap, just need a lawnmower and a place to setup. Check this out, last week at motor city raceway. You don't need much to setup a really fun track. By the end of the season it's going to be 10X better.
http://tsanrc.blogspot.com/2010/12/mcr-dec-18.html