So the way you calculate what each item is worth is you average out how much stats you get over time. The ones that you use and it gives you a buff is easy, items such as Hand of Justice, DMC: Maelstrom and Kiss of the Spider is harder because they dont have a direct stats buff attached to it or the shift the entire stat weights(KotS).
I'm going to use the stat weights of
Dps = 14 AP
AP = 1
Str = 2.4
Agi = 2.1
%Hit = 15
%Crit = 22
Anyway heres the math over several trinkets and i'll start with some easy ones.
Earthstrike Use: Increase AP by 280 for 20 Seconds (Cooldown: 2 Minutes)
280 / 6 = 46,7 AP = 46,7 Dps Points
In total: 46,7 Dps Points
Slayer's Crest Equip: 64 AP = 64 Dps Points
Use: Increase AP by 260 for 20 Seconds (Cooldown: 2 Minutes)
260 AP / 6 = 43,3 AP = 43,3 Dps Points
In total: 64 + 43,3 = 107,3 Dps Points
Drake Fang Talisman Equip: 56 AP = 56 Dps Points
Equip: 2% Hit = 2 * 15 = 30 Dps Points
In total: 56+30 = 86 Dps Points
Hand of Justice Equip: 20 AP = 20 Dps Points
Equip: 2% on melee hit to do an extra attack.
In total: 20 Dps Points & 2% "Windfury"
Someone more dedicated than me have to calculate this.
Okay so, these are harder ones to define. I'm not 100% these are correctly done. Either that or they are six times better than shown here.
Melee Hero Medallion Increase Melee Damage by 40 for 20 Seconds (Decreases by 2 with every Ability / Auto Attack that lands on the target)(Cooldown: 2 Minutes)
Since ferals attacks atleast once per second. You should get the full effect every time you use it.The sequence goes like this
Use
Hit one: 40 Added Dmg
Hit two: 38 Added Dmg
Hit three: 36 Added Dmg
Repeat this untill the stacks on the buff goes to 0.
Math: 40+38+36+34+32+30+28+26+24+22+20+18+16+14+12+10+8+6+4+2=420 Added Damage.
420 Damage / 120 Seconds = 3,5 Damage
3,5 Damage * 14 AP = 49 Dps Points
Jon Gabbar Use: Increase AP by 65 every 2 seconds for 20 seconds.
So the sequence goes like this
Use: 65 AP
Sec 1: 65 AP
Sec 2: 130 AP
Sec 3: 130 AP
Sec 4 195 AP
Repeating this pattern and after 20 seconds you whould have gotten
Edit: Math: 65+130+195+260+325+390+455+520+585+650+0=3575 AP = 357,5 AP during the 20 seconds on average.
357,5 AP / 6 = 59,6 AP = 59,6 Dps Points