Both my husband and I have degrees in Exercise & Sport Science. I am working on my Master's in the same field. I have been managing fitness facilities for five years, and my husband worked as a personal trainer for four years. This is what we have at home for working out, and trust me, it's nothing fancy:

The Step. This is a great piece of equipment for cardio and weight lifting. Turn on music or pop in an aeobic DVD and step to your hearts content, or use it as a weight bench. You can find them at your local sporting goods store or online at places like amazon.com for under $100.00. And you don't have to get the name-brand step. You just need something that is long enough for you to lay down on to lift weights, and sturdy enough to jump around on.

Jump Rope. This is GREAT aerobic exercise, but it's also hard on the joints, so it may be something you want to ease into. Pick up a rope for under $10 and get to hopping.

Mini Trampoline. Again, this is really good exercise, and fun to boot! You can go with the 'name brand' Urban Rebounder for about $100, or you can go with the off-brand for about $50. There are even DVDs that will take you through a workout.

Bosu Ball. If I could choose any 1 piece of fitness equipment, this would be it. You can hop around on it as if it were a trampoline or step (just be careful, this requires more balancing skills than either of those two options), or you can do exercises like squats, lunges, pushups, etc. on top of it, requiring you to recruit your stabilizers (your abs, back, hips, etc.) to deliver a tougher full-body workout. You can pick up the 'home' version for about $100. It's also one of the only pieces of equipment that I say 'get the real thing' don't get the off-brand. It's worth it.

Exercise Mat. It's just nice not to have to lie on the floor. You can pick up a nice foam mat (really comfy) for about $20.00.

Dumbbells/Medicine Balls/Bands. Get several sets of light dumbbells. We have 5, 8, 10, 12, & 15 pounders here at home. If you pick them up at a used sporting goods store like Play-it-Again Sports, you can usually get each weight for about $1 per pound or less, which is about $100 for all the sets I listed above combined. If that's a little pricey, start out with one or two sets. You'll also want to pick up one or two medicine balls (anywhere from 4-10 pounds each) to use when doing abs. These range from about $10-$15 each. And, pick up an exercise band (I personally prefer the thick elastic looking sheets more than the tubing with handles) for about $10.

Paper Plates. Really, they're a great tool. You can get a WHOLE BUNCH of them for about $3. Just put them under your hands when you're doing push-ups on a hard floor or under your feet while you're doing lunges, and use them as gliders, gliding your hands or feet into the movement, which engages more muscles. There is actually a piece of equipment called a glider, but why spend the money on one when paper plates work just as well? Want more ideas for how to use them? Look up gliders on the internet.

Foam Roller. This is a great stretching tool. You basically lie down on it and roll around, stretching and massaging tight muscles. You see them used a lot in therapy, but they're fairly inexpensive (about $20-$30) for a nice one, so why not use it on a regular basis?

Door-Mounted Pull-up Bar. I know you're probably thinking 'yeah, right!' but really, this can be a great tool whether or not you can do a full pull-up. Get one that has several mounting options (where you can move the bar up or down on the door frame), and keep it low to do assisted pull-ups, and as you get stronger, move it higher. You can get one of these for about $25.

Well, that's what we've got in our home gym. Add a couple workout videos to the mix, and you're all set. People have been staying fit and healthy for thousands of years without high-tech equipment, so there's no need to spend a fortune on a home gym. Everything I've listed here can be purchased for a total of under $500.00. Can't afford that? Start with what you can afford, and add to your gym as you can.