I'm sure I've told this before -
When a local Gander Mtn closed up, they had things down to 60-75% off. Mags of any manufacturer were basically gone, with empty racks. Hate to say I participated, but was paying $10 for $40 mags, so ...
EXCEPT - the ProMag panel was close to full. They couldn't give them away. I was told by an employee that they finally, in the last few days, sold them for a pittance (less than $5 each was mentioned) to a shark who flips things at gun shows.
I think that speaks for itself.