Vendors add a +80% markup to whatever you've sold them.

price(Charsi) = 1.8 * (4 * repair cost) = 7.2 * repair cost

Socketing , although it wastes a soj, doesn't add to the cost (it seems), however the gems do. I shell find socketed marts and socket them with any number and quality of skulls to determine the price increase mechanics.

I wouldn't be surprised if gems are handled as regular mod entries, as far as sell|repair cost are concerned.

The other day i took some time to see if mods are handled additively or multiplicatively, and it appears it's neither, a combination of both, or a more complicated function.
Not sure if i'll dig further, because it's just horrible testing.

That's an idea that is both plausible and verifiable. It should be fairly easy to find a weapon like a scimitar with some elemental damage, then match it with the right gem in a greyed out version of the same thing.

In this moment i'm mostly concerned with the tri- and double-dura weirdness. If (A) the repair costs and price are *.25 linked and (B) repair cost is proportional to durability, then tri-dura should triple those costs. But I'm not sure that it does:

One tri-Martel example is 32,768 to sell and 8,192 to repair. Now that does not sound like 3 times more expansive compared to a Merciless Blue Mart that is 14'487 to sell. Also whatever Charsi imbues usually comes out around that 30k mark, and I'm actually so cheap that I create a hell game just to sell that POS.

Tri-dura really COULD mean, that repair cost is 1/3 effectively, which would make socketing it a great idea due to greater savings. The weird magic find mechanics of tri-dura generation, also sound like something not overly concerned with proportionality.

• Fact 1: Socketed and White weapons are the same price.
  
• Fact 2: Gems are handled differently than common affixes, much pricier!
  
• Fact 3: Double-/Tri-Dura lowers repair cost (to 1/2 or 1/3), instead of increasing them!
  

Below are swords with almost identical light damage. Socketed weapon is almost 1.37x more expensive though (+125 gold). Whereas magic weapon adds only (+48 gold) x1.15 at the most.

That's pretty unexpected.
You sure you compared the 2 items while they were both at 0 current durability?

I didn't have to do that. Just pure logic.

1. Double dura doesn't double price. (The right sight of the picture above is proof.) - This is the un-intuitive, unexpected part really.
2. Tri-dura mart is still only 1/4 of the sale price to repair. (One tri-Martel example is 32,768 to sell and 8,192 to repair. This I tested 0/180.) - Also unexpected, surely it had to be 3/4 of sale price for repair costs to be consistent.

Hence Tri-Dura is awesome and cheap to repair.

For consistent repair cost, either 1 or 2 would have to be false. I assumed 1 wouldn't be the case when I created this topic. It turns out the weirdness of tri-dura seeps into repair costs, repair costs are inconsistent and much lower on these special weapons, go figure!

This post was edited by Korb on Jul 5 2021 12:19pm

Probably because double|triple durability is unintended in the first place.
Speaking of bugged durability, i'm not sure if it has been documented how far it survives crafting (cube and imbue come to mind).

This post was edited by xhul on Jul 5 2021 01:13pm

Crafted marts (imbues and rerolls) dont spawn +dura

Yes, A5 add sockets and A5 personalise are probably the only exception (they don't generate a brand new item).
But i'm not sure if someone actually bothered testing all cube recipes with a bugged dura item as income.

This post was edited by xhul on Jul 7 2021 04:38am

I did quite a bit of 6p.skull cubing, and the goal of making a mageplate a lot cheaper to repair by way of tri-dura, is not the worst idea. Unfortunately the resource that used to list alvls went down with indiablo.de. I did a lot of grim shields, I remember and i'm 90% sure I tried some tri-dura grims, as well, deleting tri-dura in the process.

I never did cube mageplates or ornates, I don't exactly remember why. Maybe the qlvl were too high (60 and 64 respecitively), or something, so that nothing worthwhile could possibly come out.