Base costs for common magical armors

+1 soak armor 300 drams base cost

+1 soak “Ring of Protection” 800 drams base cost

-1 soak difficulty 500 drams base cost

-2 soak difficulty 1000 drams base cost

-3 soak difficulty 2500 drams base cost
Plus, you have to pay the actual cost of the armor itself though that cost is static unlike the magic cost which is subject to modifiers below.

Universal Modifier

If Magic “armor” is a buckle or pin that can be added to any armor +40% cost.
If the person making the magic enchantment is not the person who made the actual armor, +5% cost.
f you choose to add an additional or stronger enchantment to an existing set of magical armor such as turning -1 difficulty armor into -2 difficulty you only get half credit for the reagents put into the -1 enhancement UNLESS the same person (or someone in the same lineage of wisdom) made both enchantments.

Light armor

Repairs with reagents occasionally needed -40% cost
Needs to be sewn up to work -20% cost
Light armor looks like exotic light armor -10% cost
Light armor glows or does something overtly magical -20% cost
Magic armor looks like normal light armor default cost
Light armor looks like normal clothes, slightly on the thick side +100% cost

Light armor with reduced difficulty enchantment -30% cost
Magical buckle or pin that can be added or moved to any light armor +30% cost

Medium armor

Repairs with reagents occasionally needed, -20% cost
Needs to be repaired whole to work -10% cost
Armor looks fancy and/or adorned -10% cost
Armor glows or does something overtly magical -20% cost
Magic medium armor looks like ordinary medium light armor default cost
Medium armor with reduced difficulty enchantment -10% cost
Magical buckle or pin that can be added or moved to any medium armor +20% cost

Medium armor

Repairs with reagents occasionally needed, -20% cost

Needs to be repaired whole to work -10% cost
Armor looks fancy and/or adorned -10% cost
Armor glows or does something overtly magical -20% cost
Magic medium armor looks like ordinary medium armor default cost
Medium armor with reduced difficulty enchantment -10% cost
Magical buckle or pin that can be added or moved to any medium armor +20% cost

Heavy armor

Repairs with reagents occasionally needed, -15% cost
Needs to be repaired whole to work -5% cost
Armor looks fancy and/or adorned -10% cost Armor glows or does something overtly magical -20% cost
Magic armor looks like ordinary heavy armor default cost
Heavy armor with reduced difficulty enchantment default cost
Magical buckle or pin that can be added or moved to any heavy armor +20% cost

Full Plate

Repairs with reagents occasionally needed, -10% cost
Needs to be repaired whole to work -5% cost
Armor looks fancy and/or adorned -5% cost
Armor glows or does something overtly magical -20% cost
Magic armor looks like ordinary full plate default cost
Heavy armor with reduced difficulty enchantment +10% cost
Magical buckle or pin that can be added or moved to any full plate armor +20% cost

The effects of capitalism on the magical armor trade

All the costs in the main article only cover the cost of materials used. What about the value added labor? Well, once a mage or a theurgist or a mage reaches the ability to craft permanent magical items, chances are they are motivated by things other than money. If they are the money seeking sort, they already have a cushy job as a magical retainer to some prince or potentate.
Almost no one can afford to give away magic armor for free, but frequently, magical armor is sold at cost, but only to people the mage or theurgist likes and respects. Sometimes nonmonetary favors are explicitly or implicitly requested. Magic armor crafters generally aren’t going to sell magic armor to people they don’t like any price, especially if they are theurgists rather than mages. It is taboo if not heresy to sell magical armor to heathens who are out of favor with a theurgist’s divine patron.
This is where social merits and organizational ties come in handy. If you are a loyal servant of the king (or some other powerful lord), and the king has a loyal mage on his payroll that can make magical armor, he'll probably make it for free or ask for a very small mark up, provided your track record as a loyal servant of the king is in good standing.
Likewise, most of the Scarterran priesthoods are happy to equip magic armor to holy warriors in their service. If you adventurer regularly quests on behalf of the god Hallisan, a smith priest of Hallisan would be happy to forge her some magical armor at zero markup, assuming he has the available time. If your adventurer did something pleasing to Hallisan once or twice, and never got on the bad side of the Guardians, said character can character can probably get a commissioned set of magical armor at a 5% or 10% markup. The same guidelines apply to just about any magical armor crafting theurgist.
But let’s say your character finds an NPC magic armor smith that is neutral told your character and has some time on her hands. In this case 20-30% markup is generally considered a fair price for commissioned magic armor.
Adventurers often “acquire” magical items from defeated foes. It is not normally a big deal, adventurers can often offload such items at 20% markdown in large trading hubs, or a 40-50% markdown in places where it is very hard to find people who have hundreds of silver pieces lying around.
“Used” magic armor is another story. Any would-be buyer is going to be suspicious right off the bat. Whether or not the magical armor needs repair, “If the magic armor was any good, the original owner should still be alive!” is going to be the default thought of many. There are some superstitious misgivings of wearing a dead man’s armor. It may be easier to steal a sword than steal a set of armor, but you are going to have more people asking if your “used” armor is stolen.

What Magic is required?

A theurgist needs to have Crafts ●●●● to make any variation of magical armor.
A mage needs to have some dots in Enchantment and he needs the Craft permanent magical item arcane Merit.
+1 soak armor requires the first circle spell "Create Simple Magical Armor" or the Abjuration spell spell "Protection" which does more or less the same thing.
Reduced soak difficulty armor and they need the Third circle spell "Create Advanced Magical armor"

In either case if the person enchanting the armor is not doing most the lion's share of the work crafting the actual physical armor and is imposing enchantments on armor in progress while an ordinary armor smith makes the armor, the base cost goes up 10%.
It is impossible to enchant a set of armor permanently if it's already crafted. To make an existing suit of armor magical (or to enhance an already enchanted piece of armor), the metal components have to be melted down and reforged and the non-metal components have to be dissembled and then ressembled or resewn while reagents are added and various spells casts.
For every 50 drams of reagents consumed, about four hours of work is required and about 10 points of quintessence or mana is expended.
This is on average, more than likely there are certain key points in the crafting process that require more magical infusion and certainly slow periods that require less.