Sure, it's public information, but you have to know where to find it, read newspapers every day, organize all of the information yourself, and even call the storage facilities that advertise their auctions in newspapers that don't publish legal notices online. Some newspapers even charge a fee for access to their online versions.
There are other options, it really just depends on where you're located. If you're in a small town, the most accurate method is to call the storage facilities every few weeks. If you're in a larger city, paid services save you time and help you find auctions that you might not have found on your own.
I'll give you an example - AuctionsTX.com provides the storage auction schedule for the 5 largest cities in Texas. Since our schedules are human edited, the quality is much higher than other services that automate the process.
The Dallas / Fort Worth schedule is our most difficult and time consuming schedule to produce. We spend over 40 hours a month gathering and organizing information in this area alone,
and our methods are streamlined. Ask yourself this - How much is one hour of your time worth? Most services are less than $15 a month, so if they save you several hours, the cost is more than justified.
Now, AuctionZip is a decent site; however, if the storage facility doesn't use an auctioneer, you'll never see their auction listed there...and most storage facilities don't use a professional auctioneer.
Storage Treasures is an aggregator, so there is no need to pay for their schedule...just look on AuctionZip.com, the content is virtually identical...if you catch my drift.
If you live in Texas, be sure to look up AuctionsTX.com.