I've had the movement of a Date Just seize. After doing a bunch of research and talking with a couple of European specialists, they told me that it wasn't really uncommon. Only watch I've had that happen to. None of my vintage watches EVER have had their movements seize.
$100 was a bit of an exaggeration, but I'd take an Omega movement over a Rolex movement any day, even if the Rolex looks nicer. Not so sure I'd ever buy a Rolex again. That really put me off, especially since I know it wasn't abused. The watch was rarely worn. I have a Seasmaster about 35 years old and still keeps perfect time.