Maybe have it like a background trait or something? Like something that you'd choose at character creation (only) and it'd allow you to identify ancient magical things as well as common shit that you find on the battle-field.
In general, I figure it would take years if not decades of training and experience to be able to identify shit at a glance, so anything that wouldn't just be a skill point sink would be good in my book. Possibly have only specific vendors able to identify things, and even then, only up to a certain degree; and possibly have it where higher level object identification requires a hell of a lot more gold, possibly even reagents for a vendor to identify it.
