HP 290 or Frankenstein?

I have been researching pfsense device build and I came across the the HP 290 thread on this forum. While the HP 290 is no longer at the $100 range, it is not a bank breaker at $189. Up for consideration is my old Lenovo TS440 which has a Xeon 1245v3 and plenty of ram. I have an old 60gig SSD that I can use with it. I do have an issue with the size of the case, so I would have to consider finding a much smaller case and psu which would add to the budget. It would be kind of silly to pay $100 to resurrect a old server.

My ISP is giving me slightly less than 1gig internet service. I have a Freenas server that runs my Plex server, torrent serving and hopefully Syncthing soon. I am trying to keep the electricity cost down which is a mistake I didn’t consider with my FreeNAS server.

Any thoughts or comments would be appreciated.