I have used Parker Davis many times in the past and found them lacking in strength at the cross weld.
A few years ago we switched to Ver-Mac Industries stakes and haven't looked back. Their weld is across the frame, not within it (much stronger). For a while we were ordering direct but now one of my local coro supplier carries them so I just buy what I need and large volume storage is no longer an issue. Moreover, my customers no longer complain stepping on the stakes (as intended) cause them to snap.
Over the years I have even made my own from concrete block ladder material (read the PD patent as that's where they came from) but the few cents I saved wasn't really worth it.