A Treatise on the Arms Vs. Armour of Calradia.
Often, We see warriors with the most extravagant arms, Garbed in the most rudimentary armor. I have taken upon myself to try to understand the logic behind this schism in expenses. 
First, I decided to I would divide arms and armor into “Price Pairs” That is, Most costly weapon to most costly armor, least to least, and middle to middle.
Not that I chose only “Typical” armors, that is, armors with similar Body to leg armor ratios to others. No robes or Mameluke mail!
Also, I chose polearms with cutting damage, Because polearms do the most are the most expensive, and cutting damage is the most common.
Great Long Axe -  Gothic Plate 
Long War Axe -  Sarranid Elite Armor 
Long Axe -  Druzhina Lamellar Armor 
Voulge  - Peltastos Armor 
 Each weapon goes down in price proportional to the most expensive choice, as does the armor. It is worth noting that the most expensive armor costs about double the most pricey weapon, the the cheaper you go, the closer the prices.
So, I next found the damage Inflicted on an “Average armor” (I decided 45, this guy is melee.) opponent, by each weapon.
This is damage is done by a 27/12 build. Fairly typical.
Great Long Axe  37.75
Long War Axe  36.55
Long Axe  34.15
Voulge  26.2
 Now, I find how much damage is TAKEN, by wearing each armor. The weapon they are up against is the long axe, swung by the same guy as before.
Gothic Plate 
27.65 (64% reduction) (277% effective health)
Sarranid Elite Armor 
29.65 (61% Reduction) (256% Effective Health)
Druzhina Lamellar Armor 
32.15  (58% Reduction)  (238% effective health)
Heraldic Mail with Tabard 
37.15 (52% Reduction) (208% effective health)
Peltastos Armor 
46.15
No Armor (Base Damage)
76.65
Now, it's clear (Both common sense and as shown by numbers) that you ought to spend enough money to have BOTH a weapon, and armor. The heart of the matter is, finding how much to spend on each.
If we take it for granted that having double HP means you fight twice as long, we can find a “Score” for each weapon/armor combo. 
Gothic Plate 
Great Long Axe 
(37.2K) Score=104.57
Druzhina Lamellar Armor 
Long Axe 
(19K) Score=81.28
Clearly, Gothic plate and great long axe is better, but do you want to spend dough on armor or weapons?
“Balanced”
Druzhina Lamellar Armor 
Long Axe 
(19K) Score=81.28
Armor Heavy
Sarranid Elite Armor 
Voulge 
(18.4K) Score=67.1
Weapon Heavy
Heraldic Mail with Tabard 
Great Long Axe 
(18.6K) Score=78.65
What the numbers indicate here, is that for optimal theoretical damage output, you should be spending Just about (Or maybe just slightly less than) twice as much on armor as weapons. This goes for body armor only, once you add in head and boots, (Side note, only use leather gloves, unless they are loomed) you should be paying about ¾ your money for armor.
-Over