A low-grade armor and weapon material for a Fantasy setting

[Varyon]

Let me preface this by noting what I'm looking for in this thread - opinions on what I've outlined below, as well as suggestions on how to make it plausible enough to pass a basic sniff test.

I'm slowly starting to work more on my Oubliette setting (which is for GURPS DF / DFRPG, but the thrust of this thread is system-agnostic, hence why I'm posting in this forum), and one thing I'm considering implementing is a tier system for gear, based on the materials used. Part of this is having "Tier 0" gear that is, for all intents and purposes, outright free for delvers - but you get what you pay for, and this stuff really isn't very good (but it's certainly better than delving a dungeon bare-handed and in your skivvies).

The problem is... what sort of thing could honestly be justified as free? Obviously there's going to be a bit of effort in gathering materials and putting them together, but that basically gets subsidized by the local rulers with the justification that arming and armoring delvers is worth the expense - but a combination of miserliness and superstition means actual decent gear lacks such subsidies. Peasant levies and the like are probably typically equipped with such as well (meaning peasant uprisings would similarly be so-equipped, but those are relatively rare in this setting).

The primary material I've come up with, and which I still need a name for, is a sort of very hardy vine that grows thick and is rather ubiquitous - much of the wilderness functions as though it were a paved road in decent condition due to a thick mat of this vine (in fact, the Doylist origin of it is actually my development-in-hiatus Harpyias setting, which is Space Opera; there, it's been genetically engineered to form roads on newly-colonized worlds). The vine is harvested and weaved in a manner akin to wicker (indeed, wicker containers made from it are quite common) into armor (munitions-grade, anyone who can afford tailoring is probably going to want a proper armor material), basic weapons, etc. The vine hardens into a rigid woody structure shortly after being harvested, although there should be some basic treatment - I'm thinking perhaps boiling in water for a few minutes - that will keep it supple enough to serve as flexible armor, cheap rope, etc.

That should cover tier 0 armor and bludgeoning weapons, but what about sharp weapons? Certainly, one option is to just say that sharp weapons call for tier 1 or higher, but would there be a way to justify things otherwise? Cutting weapons might be able to get away with a design roughly akin to the macuahuitl, but what material would serve for the prismatic blades? Knapping stone feels a bit too labor-intensive to be justifiable as free (plus I'd rather not have characters using tier 0 cutting weapons needing to replace their weapons constantly due to the edges breaking off). I considered scrap metal, but I don't think that's going to be sufficiently-common in a TL3-4 setting (and any scrap you find would probably be worth more to sell for being recycled than to integrate into subsidized weaponry), plus you'd still need a decent amount of labor involved to make it sharp (-ish, this is low-quality stuff, after all). Anybody have a suggestion? Another idea I had was to introduce another ubiquitous wonder-thing of some sort where some part of it can be pounded paper-thin (or maybe it starts that way) before it naturally calcifies, becoming hard and, if thin, moderately-sharp. Or maybe this is something that can happen to the wondervine under certain conditions, maybe boiling it in salt water or something? Such would normally be a bit flimsy, but wrapping it up in the above wicker wondervine can give it a solid base, allowing it to be used to cut, stab, etc (not entirely unlike a sword with a sharp-but-brittle steel edge on an otherwise soft-but-strong piece of iron).

Does all this sound vaguely plausible? And does anybody have any ideas on what to name the wondervine and/or suggestions for how to make cutting and stabbing weapons under this paradigm?