We bought a trampoline when our oldest was five. He didn't ask for it, we were just guessing. We got a good deal on one from Craigslist or similar that was brand new, still in the box, so probably like $50 or something.

He loved it and many years later he still uses it, pretty much every day that it's not raining. He's well past the age where I would have thought he would still be interested. We've replaced the mat and all the springs to keep it going.

Point being, sometimes you just don't know what kids will like.