That's what I'm currently in the planning phases for. Break-even is still the better part of a decade on parts alone, unless you get very creative (for instance, where I live, I can choose to have a special time-of-use electrical billing program where overnight electricity is ~60% cheaper than usual; you can make use of this to charge batteries overnight, rely on solar when it's sunny, and batteries during the more expensive times-of-use).

The overall point though, is that solar and/or batteries are not a viable alternative for emergency backup power, nor will they be "within the next few years." Within the next few decades, maybe.