I don't own an M1A.
I must be pretty serious about actually getting one. I have a spare military sling set aside for it, I have a few magazines for it, now the sight and a cleaning kit.
But buying stuff for a gun I don't own... Kinda obscessive.
Apparently it is common.
A tritium fore sight for the rifle is a poor man's night vision. It's an expensive rifle, and I will one day have optice for it, but those optics will cost as much as the rifle. And the iron sights won't break like optics can. I have a scope on the M1 Garand, so that will be the glass rifle. And even that is only 2.5x magnification, or so.
I'm not ready to hit bad guys in the left eye at 2000 yards. Might as well try getting good with iron sights.