To put it in perspective, people used to consume mercury-based medicine. I'm sure if the glass is thick enough, the risk of a spill (and your health) will be generally managed.
People used to do a lot of stupid stuff. If you live alone and are conscious of the risk, sure, this is not a terribly dangerous item if you're safe about it. If you live with pets or children, it's entirely sensible to be concerned about the risk. A mercury spill can seep between the floorboards and contaminate your house with volatile mercury vapors for years to come if not properly managed.