In many books (e.g. Bert Hall's Weapons & Warfare) authors state that one of the reasons for proliferation of early firearms was their price as 1 crossbow could cost like 3 or more handgonnes (arquebusses). But I haven't yet seen exact figures (e.g. Bert Hall gives just his own calculations without reference to sources).

Could anyone help me with comparative prices for early firearms and crossbows in the period 1450-1550? That would be tremendously helpful for my research.