why buy armor?

[Smersh]

It also depends on the era and the type of infantry formation. In the 1945-1965. A tank company is usually twice the cost of a mechenized infantry company, this doesn't seem unreasonable.

in the later eras, where IFV come into the fold, they are also quite expensive. So unless your buying only leg infantry (which puts you at a disadvantage on larger size maps) the price of infantry and armour is fairly well-balanced.

Most modern infantry post-WW2 fight with a APC or IFV. Unless your playing insurgency or korea, veitnam type games you should be buying mech. troops.