How do I price a 3.0 armor crafting it in 3.5?

[Shadowhunter]

Did 3.0 have different pricing for making magical items or am I missing something?

I'm considering the whole Artificer Iron Man concept (mostly because my friend who is going to try her hand at DM'ing thought it sounded really cool).
I'm looking at the following thing from Arms & Equipment Guide (which is as far as I know 3.0):

Tessellated Armor: This curiosity usually appears to be an ornate, lacquered box containing hundreds of identical metallic shapes. Numerous variations exist for the shapes, including lizards, beetles, mounted riders, and Peloran suns. When the command word is spoken, the shapes stream from the box and flow over the wearer's body, interlocking perfectly to create a single, smooth suit of +2 full plate. This armor is lighter and more flexible than normal full plate and is considered medium armor rather than heavy. Its armor check penalty is -4, and has 25% arcane spell failure. Once a day on command, the shapes wriggle and move about the wearer's body creating a hypnotic pattern effect.
Moderate illusion; CL 8th; Craft Magic Arms & Armor, hypnotic pattern; Market Price: 11,560 gp; cost to Create: 6,605 gp +397 XP

Note that last part. In 3.5, the cost to make an magical item is usually half of the market price. 6,605 times two equals 13,210 gp, not 11,560 gp.
Closest I get is x 1.75 (11558,75 gp). Also XP is usually base price divided by 25.
11,560 gp (listed prize) turns into 462,4 xp.
13,210 (double base prize) turns into 528,4 xp.
Neither of those is the listed 397 xp. So neither of those follow the same rules as 3.5.

Trying to convert:
Given that it mentions a Fullplate that counts as medium armor, easiest approximation is a Mithral Full Plate. It also happens to give the same ASF (though I don't care much about that). A Mithral Full Plate is 10,650 gp. Adding on the +2 bonus, it's listed base price turns into 14,650.
That's without the interlocking assembling magic or the hypnotic pattern thing (although I don't care about that one). On the other hand, a Tesselated armor has ACP -4 while the mfp is only at -3. The mfp also has 2 better max Dex.

I guess there's no simple way to convert this, or have I missed something?
I mean, it's probably not going to be much of a problem at the table, as I'm sure we can come up with something eventually... but from a mechanics standpoint this bugs me.
Maybe I'll just settle for the Called enhancement for 2k.

[Jackinthegreen]

Part of it is you're missing something.  The non-magical portion of the item in the case of weapons and armor has its own different pricing scheme based on the Craft skill.  Using Craft, the cost of raw materials is 1/3 of the item's final market value, not 1/2 like with magical items made purely from magical materials.

For example, a suit of +1 full plate would have its price be 1,500g starting for the full plate, then add 150g for the masterwork to get 1,650g.  Then add on the +1's cost of 1,000g to get the final market value of 2,650g.  However, the actual crafting cost is 1/3rd of 1,650g (which is 550g), and then 1/2 of 1,000g, for a total of 1,050g in raw material costs to make that +1 full plate.  2650 / 1050 =  about 2.5 or so.

In this case though...  The above does not account for the discrepancy.  When you have part of it at 1/3rd price and another part at 1/2 price, the market value will always be somewhere between 2x and 3x the price of the crafting materials needed.  11560/6605 = roughly 1.75, so something is really bonkers.  I'll try coming back to this tomorrow because now I'm curious, but also quite tired.

It's possible the 3.0 crafting numbers were different from the 3.5 ones I'm basing this post on, but I don't have the materials on hand to check.

[kitep]

It took me a while, but I cracked it.

First, you should remember that the cost of masterwork full plate is not doubled in computing the cost or the xp cost.  So,
Masterwork Full Plate = 1650gp
+2 Full Plate = 5650gp market price, but cost to create = 3650gp (4000/2 + 1650), 160xp (4000/25).
Notice cost to create does not equal market price / 2.

The Hypnotic pattern is added to the cost of the magic armor.  Entry mentions CL8, command word, 1/day
Hypnotic Pattern cost = spell_level * caster_level * command_word * uses_per_day_cost
                                = 1 * 8 * 1800 * (1/5)
                                = 2880 gp

The other stuff -- 1 category lighter, -10 ACF, -1 ACP -- are an unknown cost.  It's only -1 ACP because you already get a -1 from being master
work.  We don't even know if it's from enchantment magic or from a special material like mithral.

So we setup 2 equations with 2 unknowns.

market price = armor_cost + masterwork_cost + special_material_cost + +2_AC + enchantment_cost + hypnotic_pattern
11560 = 1500 + 150 + special_material_cost + 4000 + enchantment_cost + 2880
enchantment_cost = 3030 gp - special_material_cost


The other equation.  Remember only the magic costs are halved.
cost to create = armor_cost + masterwork_cost + special_material_cost + +2_AC/2 + enchantment_cost/2 + hypnotic_pattern/2
6605 = 1500 + 150 + special_material_cost + 4000/2 + enchantment_cost/2 + 2880/2
enchantment_cost = 6060 gp - special_material_cost*2

Combine the 2 equations
enchantment_cost = 3030 gp - special_material_cost = 6060 gp - special_material_cost*2
special_material_cost = 0 gp
enchantment_cost = 3030 gp

So we can conclude that it's NOT made of some special material.

What about xp?
xp costs = +2_AC/25 + enchantment_cost/25 + hypnotic_pattern/25
             = 4000/25 + 3030/25 + 2880/25
             = 396.4
             round up to 397 xp


tldr/don't like math; the figures check out.  The unknown cost is 3030gp.

More happy news -- since it's not made out of a special material, you can make it out of mithral for more added goodness

[Shadowhunter]

Aaah, that explains a lot, the part about only the magic parts being half price. I've only ever fiddled with wondrous items.

Now I am far too tired to cross-examine your math -I did it anyway and got everything to work out at the fifth attempt- , but colour me both thankful and impressed kitep. Thank you very much.

+++EDIT+++

If I may ask a follow-up question then, does the Extraordinary Artisan from ECS apply its 25% gold cost reduction to only the magical parts of the armor (+2 enhancement, hypnotic pattern, unknown cost) or does that apply to the cost of crafting the basic armor as well?
It seems pretty clear-cut that it should apply to everything, but it wouldn't be the first time the basic armor crafting part messed up my assumptions.
In fact, it could be the second time in record-time

In this case, it'd be 6605 gp x .75= 4953,75 gold.

[Jackinthegreen]

Extraordinary Artisan specifically says it applies to -any- item.

Thus, it applies to both the mundane and magical components of an item.

[faeryn]

Combine the 2 equations
enchantment_cost = 3030 gp - special_material_cost = 6060 gp - special_material_cost*2
special_material_cost = 0 gp
enchantment_cost = 3030 gp

So we can conclude that it's NOT made of some special material.

Actually that conclusion cannot be made. 3030 - x = 1/2 6060 - 2x regardless of if the value of x is 0 or 9999... so any special material could be possible in the construction of said item. Youd have to solve for the sum of x+y (special material + enchantment cost) to properly rule either value out of the equation.

Sure you can zero out special material and get enchantment cost of 3030 but you could also zero out enchantment cosst to get a special material cost of 3030

[kitep]

Actually, it doesn't, but it does point out I had them backwards.  Maybe I should have used parenthesis to make the equations clearer.

Assume x=0
3030 - x = 6060 - (x*2)
3030 - 0 = 6060 - (0*2)
3030 = 6060
Obviously not true, even with D&D math.  It only works when x=3030.

But the result should have been
special_material = 3030gp
enchantment = 0gp
Which makes sense, because it's usually special materials that give the types of bonuses involved (lighter armor category, -10%ACF, -1ACP)

Alas, that makes the xp costs wrong by about 121 xp, since you don't pay xp for special materials.  It wouldn't be the first uncorrected mistake in D&D books.

Hanging my head in shame for me making a math mistake