Not that swing-away hitch-mount racks are cheap. Yakimas FullSwing 4a very nice hitch-mount rack with easy swing access to the trunkgoes for $440 (www.yakima.com). You can get a pretty decent bike for that. This is assuming that your wife and child go along with you, and I wouldnt necessarily make that assumption. If taking merely two bikes, on the other hand, check out the nifty XPORT Flatbed 2-Bike Hitch Rack thats a relatively benign $179 on Performance.com.
The cheapest solution of all is to put the bikes inside the rig. That will work for two bikes, but probably not for three and the passengers. Heres how it works: Buy a piece of two-by-six lumber and cut it to the width of the luggage space. Then buy two or three pairs of front-fork mounts (the XPORT Universal Bike Mount is only $20 on Performance.com). Screw those in the board, and voila, a bike holder! I could easily fit two bikes that way into the back of a Mitsubishi Montero SUV I used to have, but, of course, you have to fold down the rear seat.
All in all, I applaud your decision to bike. Just be careful. I love mountain biking, and to confirm it I currently have a bruise on my right hip the size of a dinner plate (low-speed fall, hit rock on way down) and a six-inch red gash across my neck where a branch tried to strangle me. Which is to say, it can get a little hazardous. So pick your early trails and roads carefully. Or, work into better shape" on the road, then hit the trail.
The votes are in: Check out the winners of Outside's 2006 Gear of the Year awards, including the year's hottest mountain bike.