Like pp said, the footprint on these is huge (~ 3 foot diameter) and while you can break it down a little, it still takes up lots of space. We bought the rainforest one from Amazon because I had a hard time finding it in the stores, but you can get a good price on them second hand.
If space saving is your ultimate requirement, consider the doorway jumpers. I wondered about the safety of these, but they still seem to be on the market.