First off I would like to point out that something very similar to this was done before by Peregrinus closer to when gw2 started and I don't mean to steal the thunder of his work, I had generated a fairly similar arrangement as his independently back in the day, but looking at it again in a different light, and a long time later, took me down a slightly different path then last time.
Secondly I would like to mention that the various values I used in the construction of the spreadsheet are based on information taken from the wiki as well as an incredible data set I found produced by a redditor name Puadro I checked some of the values personally and have found nothing to suggest the data is out of date or incorrect.
So I have finally gotten as far as making a functional, and fairly universal, version of my item optimizing spreadsheet so feel free to make a copy and try it out.
Something to keep in mind though is that the biggest gap in the current form is the engineer as it is not currently supported so sorry engi players if you’re really disappointed let me know, unless someone shows interest in some upgrade I don’t think I’ll be doing any for a while. Also for reasons I cannot currently explain it does not currently work when saved and opened as an open office file.
For those of you who want to know a bit more about what I’m trying to do the most important thing is my figure of merit as fundamentally if you disagree with my figure of merit the entire spreadsheet will be meaningless to you so the abridged figure of merit is:
Value = (physical damage + Condition damage) * Survivability / (Damage - Healing)
The unabridged version is:
Value = (Power * Average weapon damage ratio * (1 + % damage increase) * (1 + ((Precision -822) / 2100) * (Crit damage + 0.5)) + (Base condition damage + Condition damage scaling ratio * Condition damage [stat]) * Enemy condition cleansing ratio * Enemy Defense) * (10 * Vitality + Base hitpoints) * ((Toughness + Base armour) * (1 - Enemy condition damage / Enemy total Damage) + ( Enemy condition damage / Enemy total damage)) / ( Enemy total damage * (1 - % Damage reduction) - (Base healing + Healing scaling factor * Healing power) * ((Toughness + Base armour) * (1 - Enemy condition damage / Enemy total Damage) + ( Enemy condition damage / Enemy total damage)))
The essence of my spread sheet takes the figure of merit above takes the partial derivatives of it with respect to: Power, Precision, Critical damage, Vitality, Toughness, Condition damage, and Healing power; and compares those values with all the available stat combinations available, accounting for unequal “cost” of critical damage, and uses the resulting value to determine which item type is the most valuable considering the current stat configuration.
So while I know my spreadsheet doesn't account for everything that it could and has some appreciable holes in it I think it covers the most important stuff and can still be informative.
If you have any questions, comments, or concerns I would like to hear them. At the end of it most of the value of this little project of mine comes from other people using it so I want to make it worthwhile for you.