I suppose your best bet, in terms of cost, would be aerobics dvds for an all-round cardio workout and overall weight loss.
I think the general consensus is that it's pretty hard, if not impossible, to lose weight in specific areas of your body and not others.
But it wouldn't hurt to do crunches and squats, etc., to tone up your difficult areas.
There is some fairly affordable fitness equipment out there that wont take up much room and wont cost too much:
Step aerobics platform:
Stepper:
Fitness ball:
To name a few examples. I'm sure there are loads more.