I am working on a spreadsheet of all item attributes their spreads and things and it got me thinking how I could easily figure out what an item is worth. I can't. More to the point I'm confused.
I set up a situation where I examine each of the attributes and how useful they are to me while I'm playing different professions. I assign them a value of 100% and attributes I'd like to have but don't really care 50%, and attributes I don't want to 0%.
I then scale the percent of my attribute vs the max for that item and times that by my weighted percent to get a scaled value. Add up the scaled values and see how that compares to an 'ideal' item. The higher the percentage the more "worth" the item has; however, this approach is very flawed as it will not account for what an item really is worth besides what market forces dictate.
So my question is, how can I determine what an item is worth without looking at the AH and using some statistics to backup my reasoning. Excluding what the Merchant has to say about the price.