Effective Experience

Effective Experience or eXP describes the amount of experience points a player is able to accumulate within a period of time (usually 1 hour) while taking the value of a players time into account. Effective Experience rates can be used to compare various training methods that differ in both GP/h and XP/h.

Formulas
The following formula can be used to calculate a training methods eXP/h. To calculate the GP/h a player has to make in order for the eXP/h values of two skills be equal the following formula can be used.
 * eXP/h = (skill-XP/h) / (((skill-GP/h) / ((max-GP/h) * -1)) +1)
 * max-GP/h = (((GP/h Skill 1) * (GP/h Skill 2)) - ((XP/h Skill 1) * (XP/h Skill 2))) / ((XP/h Skill 1) - (XP/h Skill 2))

Examples
note: the values of items and profits used in this example are not accurate or based on GE values.

Bob has to decide between the two following two training methods: With his best known money making method Bob values his time at 500k GP/h.
 * Crafting Green D'Hide Bodies at 306k XP/h with -3250k GP/h "profit".
 * Crafting Emerald Rings at 63k XP/h with 100k GP/h profit.

Green D'hide Bodies
If bob where to craft Green D'Hide Bodies for 1 hour it would then take him 6,5 hours to cover the lost amount of gold because: So in order to gain 306k XP/h though D'Hide Bodies bob would have to effectively spend 7.5 hours of his time. 6.5 Hours to raise enough gold followed by 1 hour to craft the armor.
 * (GP/h) / ((max-GP/h) * -1) = (-3250k / 500k) * -1 = 6.5 hours

This would result in the following eXP/h:
 * 306k / 7.5 = 40.8k eXP/h
 * (skill-XP/h) / (((skill-GP/h) / ((max-GP/h) * -1)) +1) = (306k) / (((-3250k) / ((500k) * -1)) +1) = 40.8k eXP/h

Emerald Rings
If Bob where to craft Emerald Rings for 1 hour then this would save him 12 minutes of his time because: So in order to gain 63k XP/h though Emerald Rings bob would have to effectively spend 48 minutes of his time. 1 hour to craft the armor followed by -12 minutes saved on raising gold.
 * (GP/h) / ((max-GP/h) * -1) = (100k / 500k) * -1) = -0.2 hours = -12 minutes

This would result in the following eXP/h:
 * 63k / 0.8 = 78.8k eXP/h
 * (skill-XP/h) / (((skill-GP/h) / ((max-GP/h) * -1)) +1) = (63k) / (((100k) / ((500k) * -1)) +1) = 78.8k eXP

Calculating the Equilibrium
Bob now wants to know: "So much GP/h do I have to make before I'm better off making Green D'Hide Bodies?".

Bob can deduct this answer by solving the following equation. If Bob values his time at exactly 1417k GP/h then the eXP/h from making Emerald Rings or Green D'hide Bodies would be equal. If Bob makes over 1417k GP/h the eXP/h from Green D'hide Bodies will be higher than the eXP/h from Emerald Rings and vice versa.
 * (skill-1-XP/h) / (((skill-1-GP/h) / ((max-GP/h) * -1)) +1) = (skill-2-XP/h) / (((skill-2-GP/h) / ((max-GP/h) * -1)) +1)
 * ((skill-1-GP/h * skill-2-GP/h) - (skill1-XP/h * skill2-XP/h)) / (skill1-XP/h - skill2-XP/h) = max-GP/h
 * ((100k * -3250k) - (63k * 306k)) / (63k - 306k) = 1417k