The Umbrel Home is basically a $400 NUC whose power draw should idle around 10-12 watts, with activity around 30-40 watt or so.

The Dell Optiplex power supply can accomodate up to 180 watt draw if ever needed. Id speculate itd idle a little higher around 14 watts and actively be pushing around 65-70. Where im at that translates to an operational cost difference of about $40/year. So in theory, if this node remains in service longer than 5 years it may be cheaper to have gotten a NUC.