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.
if you use the official numbers (5% repair of price, 4% break chance (that's atleast what i've seen)) you can afford the upkeep of 25k worth of equipment per multiplier. If we use your average multiplier (i'll just use 1,8, dunno how many rounds the average player stays; it also depends on what multiplier you have when leaving), that means you can afford to permanently use 45k worth of equipment.
Now, i havent made any actually tests, but i've kept an eye on my gold while playing with 39k worth of equipment, and i actually earned a noticeable amount of gold. Now, i dunno if you were just unlucky and the officials numbers are true or if i was just lucky, but lucking at my observations, i'd say that depending on your skills and how good you are at changing servers at the right time, you should be able to afford 40-50k equipment.
According to the multiplier compared to the amount of rounds you play on a server, those numbers won't be correct for many CRPG players, as many players only leave servers at x1, and for those numbers to fit, people should also leave with multipliers.
Another way to increase your average multiplier is to change server if you are on the losing team at round two, as the auto balance wont make big changes from round 2 on, so your chance of winning the next round will be smaller than 50%, and if you change server it will be 50%
