Last week, I saw the NOVA episode about Viking swords, specifically those known as Ulfberht swords. For a while, I was tempted to scour the RPG forums for people objecting to the program because it violates their imaginary facts (you know they're out there...) But nah, I can't be bothered, even for entertainment purposes.
But the video is good, and does raise the question "how do you distinguish between swords (or anything else) made of different materials?" Because a lot of the differences come down to things like breakage, as illustrated in the program. Or, in the case of bronze vs. iron, bronze is more expensive and has to be recast if damaged, but iron requires higher technology to forge. Typically, if something is on an equipment list, players want it to be available NOW, and hate things like "yeah, this weapon is cheaper, but it's not available in your area". Or, for that matter, anything without a mechanical benefit.
You can get a little bit of weapon breakage going on if you adopt a suggestion I made once to allow Trollsmyth's "Shield Shall Be splintered" rule to be used for weapon parries as well. High-quality steel weapons like the Ulfberht sword won't break, but will be knocked out of the defender's hand when used to parry a weapon of lesser metal. You can maybe also apply this to "miss by 1" attack results (weapon breaks against opponent's armor or shield; a weapon of higher quality material gets stuck in a shield, if any, instead of breaking.)
I previously suggested 5+ on 1d6 rolls to test for weapon breakages, and I'd still use that in some situations (Ulfberht sword parrying Ulfberht sword, for example.)