Unless you get your power for free (or a free rack server), you’d be better off just building a tower to start with more modern, power efficient parts.

Also, you didn’t mention if you had a rack, if you don’t, definitely avoid rack mount servers for now.

I have several ESXi hosts, which automatically turn off and on as needed by vCenter based on server loads.

Otherwise, I don’t turn anything else off.

I have three 750s I haven’t had the time to swap out our 730s for yet. You bet those are coming home once I finally do.