How long will that $1,500 battery power my house? It's still not possible to beat hydrocarbons in terms of energy density, and if you are looking to weather a multi-day outage, it's energy density you care about...
$1500 would give you 4.25KWh. The average home averages 1KW, so you'll have 4.25 hours.
Obviously you could get more efficiency with a stationary battery.
Even cutting to 80%, you get an extra hour. 50%, and you've got 4. I am having a hard time finding refrigerator specifics, but around 1000KWh annually seems to be on the high side. This gives you 1.5 days on the 4.25KWh battery.
(for homes with nat gas it's a no brainer)