The value of a wall of iron

[Jack Simth]

Iron is listed as a trade good: 1 sp = One pound of iron

Wall of Iron is 1 inch thick per 4 caster levels, one 5-ft square per caster level
Using 1/4 inch thick per caster level for the math, that's 25 ft^2 * 1/48 th ft per caster level^2; 0.520833333333333333333333333333333 ft^3/cl^2; 0.014748333333333334 m^3/cl^2; 116.128376666666671916 kg/cl^2; 256.01945507563335 lbs/cl^2. For caster level 12 (a threshold - 3 inches thick, so that the above formula applies properly), that's 144*256.01945507563335=36866.8015308912024 lbs, which translates to 36,866.8 sp; 3,686.68 gp, 368.668 pp. The spell costs 50 gp for materials, and Caster level x 60 gp = 12*60 gp = 720 gp to hire; so for 770 gp, you can "purchase" 3,686.68 gp worth of iron, for a profit of 2,916.68 gp.

Sources:
http://srd.pbemnexus.com/equipment.html
http://srd.pbemnexus.com/goodsAndServices.html
http://srd.pbemnexus.com/spellsTtoZ.html#wall-of-iron
http://www.allmeasures.com/Formulae/d1/d2/d3/Results2_2.asp?formula=2&material=Iron+[Fe]
Plus a calculator, of course.

Or am I just insane?

 

[Crothian]

well, transporting the material to the buyer will cut into that. And when the Dwarf mining guilds come by to rough you up because you know they are union you might regret doing it.

 

[dcollins]

Iron is listed as a trade good: 1 sp = One pound of iron

It's pretty common for D&D economics to not work out in a reasonable way. Prices in different parts of the system are generally not synchronized or economic-simulated against each other. This would be an example of that.

Usually the job at this point is for the DM to decide what his campaign world looks like, and rationalize issues like this after-the-fact. Let's assume that PCs should not have a venue for free money like your calculation suggests. Then the DM has to make up a reason why it doesn't work. Here are some options:

- The magic iron is a substance that cannot be worked, and thus has no value.
- The wall of iron is too big to transport/handle at a smelter's.
- Wizards refuse to do this, reserving their own right to profit from it.
- Etc.

 

[Jack Simth]

Let's see... 36,866.8015308912024 lbs; untrained hirelings cost 1 sp/day; at str 10, they have a maximum load of, what, 100 lbs each? They can drag 5 times that, so 500 lbs each - you need 74 of them (74*500 lbs = 37,000 lbs), at a cost of 7.4 gp, bringing your profit down to 2,909.28 gp. Trained hirelings for the same task cost 3 times that, bringing your profit down to 2,894.48. If you need to buy 50 feet of rope for each of them, so they can all pull on it, that's another 74 gp, for a total profit of 2,820.48 (using Trained Hirelings). If you make it one, big, long, 5-ft wide steel slab, and just have everyone stand underneath and lift (no rope needed), you need 370 trained hirelings (str 10, 100 lbs each, at 3 sp each), for 111 gp transport cost, with a net profit of 2,805.68 gp. Transport costs don't cut into it that much.

Granted, BODYGAURD fees may get up there....

 

[Jack Simth]

It's pretty common for D&D economics to not work out in a reasonable way. Prices in different parts of the system are generally not synchronized or economic-simulated against each other. This would be an example of that.

Usually the job at this point is for the DM to decide what his campaign world looks like, and rationalize issues like this after-the-fact. Let's assume that PCs should not have a venue for free money like your calculation suggests. Then the DM has to make up a reason why it doesn't work. Here are some options:

- The magic iron is a substance that cannot be worked, and thus has no value.
- The wall of iron is too big to transport/handle at a smelter's.
- Wizards refuse to do this, reserving their own right to profit from it.
- Etc.

Yeah, I know - no DM would allow PC's to do this (at least, not more than once....) but the math works out pretty well, and it would make an interesting stop for a caravan (Caravan Gaurd PC: Wait.... weren't we carrying chickens when we arrived? Where'd the iron come from? We are out in the middle of a desert, with no mines in a hundred miles - how in the world did you get THAT MUCH iron?)

 

[Crothian]

well, you might have to transport it longer then a single day, it is rather big so it might not fit on the roads especially in the city where streets are smaller. You also need to be able to find 370 people to do this and that in itself might not be that easy.

 

[Crothian]

Yeah, I know - no DM would allow PC's to do this

Why not? it is not that much money for the PCs by the time they get to a level of being able to do this. There are just more factors trhen simply creating and then selling the iron. Finding a buyer, transporting it, interferring with trade regulations, possiblity of crossing Wizard Guilds an certain craft or mining guilds, taxes on it, etc. So, I have no problem with players trying it but there is no reason they should expect it to be simple.

 

[sukael]

Yeah--it's an apparently easy form of profit, but then you have to factor in the time and effort it takes get the iron to wherever you want it. (Unless you, say, cast the spell just outside a smithy's shop...)

 

[Stalker0]

I think the suggestion that the iron cannot be worked is a great compromise so I don't have to change teh spell to wall of gold

See this is what you get when you change spells. Permanent to instantaneous duration...and everyone's got iron up to their ears!!

 

[FreeTheSlaves]

The problem with coming from a pure economic approach is that no economic system is independant from it's environment. You have governmental policy, cultural sensitivity/social norms, religious pressures, economic capacity, infrastructural issues, geographic obstacles and the random element (of say a war) affecting the economics of the situation.

Generally it is a bad idea to try to disrupt the delicate economic equilibrium of some kingdom without the express consent of the powers that be. Those that have their power and wealth (or something to lose) springing from the status quo will move decisively to protect what they have.

Also in the case of the wall of iron. If this is the most efficient means to produce iron, why would it not be the existing method? This idea that the PC's will think of it first doesn't cut it because the spell existed beforehand and no doubt the idea would have occurred to an earlier wizard. This implies it either doesn't work, or isn't allowed, or is the norm? If it is the norm the PC's would have as much success as new bank have... not much.