I admit I'm far from expert on Ancient warfare, as my interests are in medieval warfare, but you need to learn to read and understand what you read.
Where did I said, that swords and armor were not expensive? Of course it were, as the iron ore was much more expensive than the wood.
But yes - all men and women can hold, carry, use to an extent a sword, shield and armor if they take 1.
The power of a weapon it's not in the weapon itself, but depends on the skill of the user.
I can bet my house, that you(and I) can't beat even with the finest sword some shaolin monk using a stick.
Indeed it was, is and probably will be in the future as well - 1 word - evolution.
Slings ->Bows/Crossbows ->Arquebus/Muskets etc. -> modern automatic rifles/Snipers
Let's see melee weapons:
Swords/Spears/Axes/Hamers etc.(from different materials through the ages) -> lighter cavalry and inf sabers -> very rarely used modern combat knives and bayonets
You see - if melee wpns were that superior to missile wpns as you think, the evolution was going to be much more different.
In skillful hands both missile and close combat wpns are very deadly, but the later have the disadvantage of needing to be close to the victim and the 2nd have disadvantage when being close.
Also let's not forget Atila the Hun and all other "Horse Archer heavy(light troop heavy
)" tribes and nations, who were great threat to the Roman Emire.
However my point was - if
Aeimnestus want realism = missile as deadly as melee wpns in most cases(depends on training, quality of bow/arrow and quality of armor/shield), if you let them shot at you from effective range(roughly 2x less than it's max range).