$69 for 28 hours of backup sounds like a pretty good deal, well spotted.Azoo non stop air pump has battery backup and they are nice.
Azoo Non-Stop Air Pump with Battery Backup - AquaCave
They are a bit expensive on that site, try ebay. I would give that pump 5 stars.
Sounds like a bargain! The vast majority of power outages will be under 28h, this looks like a good, well priced solution.they are, I refurbish them at work. You can get whole rebuild kits for under 5 bucks through azoo.