Some information in this post is now outdated. Please see my new thread for the updated information.I have concluded a relatively simple test to determine the current rate of maintenance and the corresponding amount of equipment a character can afford to field. Over the last generation of my character, I have recorded my experience and gold multiplier for every round I have played since I could use my standard equipment. Additionally, I have kept track of the experience and gold I had when I first started using this set of equipment and have not purchased any items nor changed my equipment since beginning the test. All rounds were played on the 100 man NA battle server while it was well populated. From a set of 482 rounds, I have determined the rate at which gold is lost to maintenance.
For these calculations I used the following values extracted from my test:
starting experience: 1136000 exp
ending experience: 8738000 exp
starting gold: 672310 gold
ending gold: 795081 gold
generation: 11
average multiplier: 2.19
equipment cost (buying price): 14220 gold
My character gained 7602000 experience and 122771 gold over this period. However this amount of gold gain has been reduced due to maintenance. The gold gain without maintenance is proportional to experience gain and character generation such that:
gold gain/exp gain = 50 gold/(1000 exp+100 exp*(generation-1))
For my character:
gold gain/exp gain = 50 gold/2000 exp = 0.025 gold/exp
So without maintenance I would have gained:
7602000 exp * 0.025 gold/exp = 190050 gold
Therefore, over this period I lost 67279 gold to maintenance. As gold gain, experience gain, and equipment breakage (to the best of my knowledge) are incremented at regular intervals, or clock ticks, it is perhaps best to look at these tick time units instead of number of rounds. The number of ticks included in this set of games can be determined:
Number of ticks = (end exp-start exp) /((1000 exp+100 exp*(generation-1))*average multiplier)
For this set of data:
Number of ticks = 7602000 exp/ (2000 exp * 2.19) = 1735.6
The amount of gold lost to maintenance per tick was 38.8 gold. To determine the rate of maintenance, that is the gold lost to maintenance each tick per gold worth of equipment:
rate of maintenance per tick = (gold lost to maintenance per tick)/(equipment cost)
Using my values:
rate of maintenance per tick = 38.8 gold / 14220 gold = 0.0027
As this rate of maintenance per tick is normalized for generation, average multiplier, and equipment cost, it should be independent of character and player. While not necessary for further calculations for sustainable equipment value, the chance of breakage per tick can be determine from rate of maintenance per tick since the cost or repair is known to be 5% of the item buy price.
chance of breakage per tick = (rate of maintenance per tick)/(cost of repair)
chance of breakage per tick = 0.0027/0.05 = 0.054
This result shows a 5.4% chance of breakage for each item each tick. This chance of breakage is greater than values I have seen given by chadz, but could be the result of outdated change logs, the development team generally being a bunch of trolls, or the breakage checks not actually being synchronized with the experience and gold ticks.
Going back to the rate of maintenance per tick value of 0.0027, we can determine the sustainable monetary value of equipment using:
average equipment cost = 50 gold * (average multiplier)/0.0027
From the immediately preceding equation, it should be obvious that the average multiplier of a player is important to what equipment they can afford. Though player skill is a factor in your multiplier, it is not easily quantifiable and is beyond the scope of what I will attempt to cover here. Suffice it to say, average players will win about 50% of their games while good players would expect to win more while bad player would win less. From this assumption of 50% win rate, the average multiplier of the average player can be determined. Begin with the first round of play after joining a server the average player's multiplier would be:
1x for the first round (100% chance of 1x)
1.5x for the second round (50% chance of 1x and 50% chance of 2x)
1.75x for the third round (50% 1x, 25% 2x, and 25% 3x)
1.875x for the fourth round (50% 1x, 25% 2x, 12.5% 3x, and 12.5% 4x)
1.9375x for the fifth and following rounds (50% 1x, 25% 2x, 12.5% 3x, 6.5% 4x, and 6.5% 5x)
The following plot shows the cumulative average multiplier of a player as a function of rounds after joining a server.
The most notable feature is the asymptotic approach to a 1.9375 multiplier. This means that players that play a few rounds in one sitting or between changing servers or having to rejoin servers would be expected to earn less gold and experience than player that play for extended periods. To put a scale to all of this, the average player who plays in 15 round sittings (about 1 hour on the 100 man NA battle server) could maintain 33730 gold worth of equipment continuously while an average player who plays in 30 round sittings could maintain 34880 gold worth of equipment continuously.
TL;DR version: You can continuously maintain an average equipment cost equal to your average multiplier times 18520 gold. Your average multiplier will most likely be a little less than 2x. Most players can have equipment worth about 35k without significant financial hardship.
Some information in this post is now outdated. Please see my new thread for the updated information.