If they were not then, they certainly are now! I want a new one for my sword which is set to cost an arm..then the chape etc and belt fittings for hanging cost a leg ;)

The accounts of the household of Henry IV of Castilla, in 1462 have both items listed:

Sword scabbard: 35 or 40 Maravedis
One sword: 150 ms.

Even taking in account that it was for the king (not sure of that), the scabbard doesn't seem too costly when compared to a sword.

There are more armoury items listed costing around 35 or 40 ms to have another reference, too:

A spear: 40 ms.
A fanega (55.5 L. aprox) of barley: 30 or 38 ms.
A pound of copper: 35 or 40 ms.