How often do they honestly use them?
We have a garden with a paved garden path. Small squares of paving, it's pretty level but I'm not sure if it's suitable for skating on. We live on a steepish hill. There is a small park nearby but I'm not sure if going round and round on a basketball court sized bit of tarmac is going to hold interest for long. I did suggest DC could go with DH when he runs, but he prefers to run on path type routes rather than on the road.