You can go with an “intermediate solution” until you can afford the autostandby configuration.
Buy a cheap portable genny and get a bunch of extension cords.
Make sure to shut off your main breaker while you’re powering things with the generator.
And, consider the fuel your generator will need.
I have a 2400 watt generator right now that I mainly use to back up my basement sump pump if we lose power. If it’s not used by the sump pump it’s enough to power most of what I would need.