Taking your kid's age into account...would a tabletop electronic drum kit or something like this suffice for the time being? It's cheaper and you don't need to worry about it taking up space. Here's another example. I'm no expert drum player but the drummers I personally worked with in the past do own at least one of these kits (in addition to their acoustic and also digital drum kits), especially if they just need some casual practice.
Disclaimer: I haven't played drums for several years