I know we are getting OT here but just to highlight the divide.and yet idea makes millions every year, the dollarstore alibaba & dhgate are likewise happy to sell you a wide selection of poor quality items vhurnerd out in huge numbers by modern factories .
If material cost & sale price were both 1/10th there would never be no reason to ever risk the downsides. Yes if you were buying one dagger it might make sense to spend the extra for the good one, but if you were buying one thousand daggers for an army where you expect 80% of the troops are going to be barely capable of using it & at least 60 % of them to never use it for anything more critical than peeling an apple you might buy the cheap daggers and put the savings towards quality boots that allow them to marge at good speed. Of course if you want to sell a bunch of poor quality daggers the difficulty is in finding a buyer interested in buying a thousand sharpened sporks
So if we look at a cheap metal dinner knife, nothing fancy (but designed for long term use), you can get one for about $.75 on Amazon (literally just looked).
Meanwhile, we can get plastic knifes for about $.02 a knife. One the one hand, plastic knives can normally be used multiple times without issue, but they are designed for 1 use and certainly wouldn't cut all the things a metal knife could, so a reasonable approximation of "poor quality"
so right there we are looking at a 37.5x price difference, a hell of a lot higher than the 2x we have now. Aka it takes a very large difference in price before people would utilize a one use disposal item over a permanent one.
In terms of an army, it does make sense to fit your foot soldiers with low quality goods, they are disposable units after all. But....again the poor quality items are just TOO POOR. What the condition technically means is that after 1 round of melee combat, every single one of your foot soldiers would have no weapon. Yes soldiers die quickly in battle but not that quickly.... and now your foot soldiers have no means of fighting back against the enemy.....aka they will be slaughtered. No battle commander (even a cheap one) would think that's a good idea. At that point you might as well just have every soldier go into the woods and find a sharp stick.
I do appreciate the debate because I think I've come around to my real issue. I thought it was cost at first and sell price, but it at the end of the day its not. The real issue is that poor quality is not in fact "poor", its "garbage quality", "unacceptable bad quality", "insert your expletive here quality". Items of this kind of quality are so terribly unusably bad, there is no reasonable scenario that anyone would ever ever use them, unless they are were just completely swindled.
So the reason answer to me....is just fix what poor quality means. Going on what Faolyn said, probably the easiest means is "when you roll a 1 on an ability check or attack roll with this item, the item breaks", something like that. That is still bad, but its at least workable.