Doug,
I'm sorry this happened to you.
With that said, I don't consider that hydrometer junk. Swinging float-arm hydrometers are amazingly accurate considering they are basically a piece of plastic.
Here's my recommendations whenever buying a float-arm. Before you leave the store, use it in the stores tank to make sure there's no problem with it. These instruments are highly sensitive to drops. The unit you purchased could have been dropped during shipment or even while at the LFS. Even if it's good from the LFS, if you accidentally drop it, you need to make sure it's still calibrated correctly again.
Beyond the dropping issue, there's the issue of built up salt giving false high readings. They MUST be rinsed after every use with fresh water. This is preferably RO/DI water because even tap water has dissolved salts in it. However, tap water is better than allowing saltwater to dry in it.
Periodically, soak them in white vinegar and then rinse them out with fresh water.
