Mine always snap before they get blunt, and I know why that is: I use a small bandsaw, where the radius of the wheels puts a lot of stress on the blades. I haven't done it yet, but I am considering getting them re-welded.
All bandsaw blades will eventually snap, as the material gets tired out running around the wheels. Bigger wheels = less stress = longer lifetime.
There's nothing in the book that says you cannot resharpen a bandsaw blade, but at the same time you cannot cheat physics, either.