Whatever you are buying: If you have some device in mind, check the idle power consumption. Your server is running 24/7/365. If you buy something with a high consumption, that will be hard on your power bill.

10W = 87,6 kWh a year @ 0,25 Cents = 21,90 per year 50W = 438 kWh a year @ 0,25 Cents = 109,50 per year

That really does matter