IMO given what you've said above, eBay the server and use the funds to buy a compact NAS capable of RAID-1.
Part being in an IT function is saying, "What you're proposing is stupid. I am the expert and I propose we should do this."
Of course at some point you may have to rollover and say, "I still think you're an idiot, but I will do what you have requested as you are the end customer." (in an email so there's no come back on you).
* You may want to modify the language somewhat depending if the person is able to fire you