Don't forget, there would not have been a lot of what 3rd Age people would easily recognize as weapons. While the scope of the war meant they were reduced to low tech in some times and places, it stands to reason that would also preclude lots of indestructible weapons being made. In general, if they had the tech, they were going to make shocklances and such.

Also, power-wrought weapons aren't really a game changer. They're more of a convenience, albeit a highly useful one. Having a power-wrought sword doesn't make you better in a fight. It MIGHT cut through armor a little better, but these aren't said to be particularly sharp, you never see mention of using it for things like slicing hairs or cutting flies in half. It's just that they will be just as ready for action after a long day of cutting through opponents as they were at the start. The meat sack holding the blade on the other hand... A power-wrought blade does not gain any advantage of accuracy or range. It might take some more hit points, but no one ever says it's easier to use. For instance, Lan doesn't suggest that Rand having a power-wrought blade will give him any more of an edge in dueling Couladin. Darlin's mundane blade was just as effective against the fog monsters as Rand's. Rand doesn't feel like he's worse off holding the blade he takes from the renegade Asha'man he kills in Far Madding, having left his own back at the inn. (by the way, one of the things that really annoyed me about Perrin & Neald was the Aiel Maidens pushing ahead of everyone else, demanding special priority yet AGAIN, when their weapons were the worst suited to a metal upgrade. Unless Neald could Align the Matrix of the wood shafts, their spears are not suddenly better, but the power-wrought heads are more vulnerable to loss, being at the end of a mundane piece of wood - Aiel carry them in multiples for a reason, and it's not because of the inferior quality of the spearheads)

So I doubt there were tons of them made for the War of the Shadow. Blademasters are not all that common and not many of them have access to a power-wrought blade, while unadorned swords like Lan's Malkieri legacy seem to be even more rare. What's interesting is that Tam was perfectly willing to let his sit under the bed for 2 decades. If they are priceless, selling it could have been a major bump in the family's material status, especially given Kari's disapproval and Tam's own mixed feelings about the blade and presumably his military service. So maybe they are fairly common, and blademasters are more common as well. No one really seems to note who blademasters are, the way they do Great Captains. Until we see their weapons, there is no mention of the degree of skill possessed by Eamon Valda or Toram Riatin. You'd have to figure most Warders are around that level, and there has to be several hundred of them. Tam and Valda serve as ordinary officers, rather than as elite specialist fighters.

In general the reaction to Rand's sword has more to do with what people think it says about his skill, rather than the fact that he is carrying around a singularly rare and priceless artifact. I'd say blademasters are probably about as rare as high level martial arts black belts, and power-wrought weapons about as common, but irregular and ungoverned circulation issues like Tam's retirement mean that a blademaster can't always be matched up with an authentic blade.