Hmm after experimenting for a bit, I identified some whites (using superior identification kit), usually around 50 gold each. Out of around 10 white items I identified, only one went up from 54 to 98 gold in value, the rest only went up by around 20 or 30 gold each.
As for salvaging crafting materials from blue items, I actually got lower gold (forgot what items I salvaged from) than if I had just sold them to the merchant. I only got one rare crafting material and of all things it was a monstrous eye worth just 100 gold.
I guess it's really a gamble, I'll just stick to identifying the real unidentified items and salvaging obviously good upgrades and inscriptions instead of wasting money trying to squeeze out 20 more gold from whites lol