The UPS we are referring to, APC Smart-UPS, Line Interactive, 1500VA, is approx. 0.03386881BTC. It is my go to UPS of choice.. on 1,000W it will yield a runtime of 6mins...
Now, if you wanted 24 hours @ 1,000W.... 1 x APC Symmetra LX 8kVA Scalable to 16kVA N+1, Tower 208/240V and 4 x APC SYMMETRA LX EXTENDED RUN TOWER W/9 SYBT5 , 208V, 2.32111771BTC
Or you could just chain a bunch of external batteries to the APC. I have 8 12-400 batteries wired into an older APC Smart UPS 1400 that can do 16 hours at 500 watts. More than enough to run the fridge, circulation pumps, lights, and some chargers.
Also these days your "emergency servers" can just be raspberry pi's with 1tb SSD cards. Those take like no power to run.