Last year was the first time I saw a family that owned their own bounce house and just set it up in their living room. At the time I thought, what a lucky rich kid, that must cost at least a thousand dollars. But my wife looked into it and found out that bounce houses are surprisingly cheap these days. She got our kids this one last Christmas, its currently going for $234 on Amazon:
The kids love it and its still going strong ten months later, despite substantial use from kids and the presence of two sharp-clawed cats. It was certainly a bigger hit than the other major gift we tried last Christmas- telescopes are surprisingly hard to use.