There is a page under the resources tab on Maxroll detailing what could be a great first step for you on this. Its called "Valuable Magic Items".
I know what's valuable but what im trying to get at is that it might not be worth identifying even items that could be the most valuable because the odds aren't worth the time spent identifying. Ill write up an example and maybe this will help clarify things further:
-Situation 1: Pick up and identify all magic monarchs, barb helms, Sorc weapons, claws, druid helms, warlock books, etc. (remember, this is going to add significant time to your runs especially if you're like me and have a full inventory of charms)
-Situation 2: Only check for ethereal white items/socketed bases (easy to pick up and toss, no need to have inventory space and no need to identify - just click with inventory open and drop if not ethereal)
Of these two situations, who will end up with more forum gold? Situation 1, who clears significantly less mobs because time spent identifying, town portaling, stashing, buying ID scrolls, etc but has the opportunity to find more valuable items, or Situation 1 who clears far more mobs.
I'm sort of giving arbitrary info here but the idea is are some of these items, while having the opportunity to roll an extremely valuable item, not worth picking up and identifying because the odds are so low and the time it takes to do this adds to your run times. I'm getting pretty granular here. Just a discussion, was curious how everyone else operates while playing.