A: There are a number of contemporary sources that may be referenced in order to get an accurate idea of the cost of armour during the fourteenth and fifteenth centuries. The chief source of income for nobles and gentry was through the collection of rents and taxes. Every landowner worth his salt had at least one clerk on his payroll, and professional clerks are, obviously, very meticulous record keepers. There are extant documents that detail the amounts of rent collected from various tennants, inventories of individual estates and manors, and salaries of individual servants and retainers. It is from these inventories that we get a glimpse at the value of a suit of armour..