Actually, now that I'm actually taking a good look at those materials, most of them are seriously overpowered.
I don't know why chivardium is cheaper than adamantine; it's almost strictly superior even without the metal-melting trick. (Which really really really needs a save associated with it. Or, better yet, to die. Balance issues aside, if you're fighting someone with a chivardium shield, how would you decide if your sword hit the shield on any given strike?)
Flux iron is fucking crazy - do you have any idea how good force damage is? Hint: it is the best kind of damage in the game, bar none. It is strictly superior to absolutely fucking everything. Nothing is immune (except for one epic-level dragon and maybe a couple gods). Nothing resists it. It ignores incorporeality and etherealness. It ignores damage reduction. It is worth way the hell more than 500 gold. (Also, 'force damage' is not, strictly speaking, a real thing. It's 'damage from force effects'. This is why there's no such thing as force resistance - it's not an energy type.)
Even if you take out the ability to be force-infused it's pretty ridiculous. Dealing fire or cold damage is nice, and certainly worth more than 500 gold, but it's not too crazy; damage reduction isn't much more common than fire and cold resistance. Electric and acid damage are better, but not by too much. Sonic, though? Sonic damage is the king of energy damage. Sonic resistance is almost nonexistent, which is why sonic damage is always more expensive.
The armor options are also outrageously underpriced. Have you even looked at how much energy resistance costs? Enchanted armor of energy resistance, which gives resistance 10 to the appropriate energy type, costs 18,000 gold. That's more than ten times what you'd pay for a suit of flux iron medium armor. Just kill this metal; I'm pretty sure it's unsalvageable.
Green steel is fine, except for the critical threat range thing, which is completely ridiculous. There are threat range increasing effects. There's the Improved Critical feat, which you have to be at least 8th level to take. There's the keen edge spell, which is third level and lasts for less than an hour when you first get it. There's the keen weapon ability, which is fairly affordable at a +1 equivalence (minimum price 8,000 gp).
This is better than any of them. Oh, and none of those stack with each other, which green steel appears to do. And it costs 850 measly gold pieces. You want to know what other material has critical-enhancing properties? Solarian truesteel. It gives you a +1 bonus on your critical threat confirmation roll. This is a small bonus, and the metal has a correspondingly small cost: 1,000 gp. Increasing a weapon's critical threat range, on the other hand, is a major bonus, and this has an even smaller cost.
Amber looks okay - it's not as good as mithril unless you're an arcane spellcaster, so, fine. Cardoly coral is probably somewhat underpriced, but not too badly. I think there's an existing material that does that, actually, but the place to look would be in Stormwrack, which I don't have. Morophot bark has one of those oddball bonuses that don't come up much.
The other problem you have is that you've forgotten one important fact: Special armor materials often give bigger bonuses when you make heavier armor out of them, but the ones that do always cost more for heavier armor. Even the ones that don't often cost more. It's just common sense; 50 pounds of metal for a suit of full plate is bound to cost more than 25 pounds for a chain shirt. Usually medium armor costs twice as much as light armor, and heavy armor costs three times as much.