Repairs is basically about luck, honestly. Some days are good, some bad.
I usually keep myself restricted to light armor until I have a 10k gold buffer and roll with my usual stuff until I get down to 5k.
math != luck. First off, 3k is not much of a bank, so you need to build up a bigger reserve, say 20k at least. From there as long as you are using under 20k~ loadouts you will always gain a net INCREASE to gold over the course of time. One day may be particularly bad and see alot of repairs and you could drop 3k-5k. Other days will be better and you will GAIN money.
http://wiki.c-rpg.net/index.php?title=UpkeepWPF can also influence repair costs, although I'm not sure how it operates. Not having much WPF in a weapon increases likelyhood it'll need repairs
Smart players will change their equipment loadouts based on their multi's, so instead of using one of the most expensive weapons in the game if you have a x1 or x2, use something less expensive like say a Dadao or bardiche