It is not so much a matter of money as convenience; moving your mouse over items is much easier than bringing everything to someone and identifying them one at a time. I put 3 skill points into Identify, got one level as a quest reward and found a belt with a bonus to Identify.
Once you move or run you mouse over an item, or hit the alt key while standing nearby, the properties of the item are set. You have to use Identify if you want to be able to quick save before doing this, then quick load to get the best stats on an item (running/teleporting to a merchant makes this much slower).
