This definitely seems like one of the best prices I've seen for one of these.
I've thought about these units since the Xbox Series consoles were first introduced. While I like the general concept of an easily removed storage expansion it was clear early on the cost was never going to make a lot of sense. For whatever their next console is I would love to see them take this general design but instead just make it a M.2 NVMe caddy. Even if they charged $50 for it I think most people who actually need expandable storage could see the long term value.