From the way I understand it, repairs work like this:
There is a 4% chance that each of your items break every single time there is a tick of experience. As far as I know, this still counts when you're dead, so if people are delaying, you've got a higher chance of having broken equipment, but you will also gain more money.
You'll have good days and bad days because of the fact that sometimes you won't always get onto the winning team, you'll get stuck on x1 for an hour or so and thus, with heavier equipment, you will lose a lot of money, but there will also be times where you get x5 for a long stint, although these two things are rare, the average multi that you get is roughly 2.2/2.4 so you'll be gaining between 100 and 150 gold each round.
There are several guides that explain repairs in more details if you check the beginners guide section and you'll also find that there's a lot of different ways to make money on the market if you really really want run around in full plate for a month!
Also:
The repair costs run at 7% from my understanding, Longbow costs 11,100 and costs 777 to repair. 11100 * 0.07 = 777
Hope this helps slightly.
EDIT: I don't think the system needs changing away from the repair costs sizes that we have right now but I do believe that it needs changing based on another factor, such as the "all thine hard work has payed off" thing so that it decreases the repair chance, very small maybe just 0.1% each time to a maximum of 1 or something similar, but that would also mean increasing the levels that you're allowed to gain this, but each time over level 31 you won't increase your crafting skill for strategus or something like that. I'm not very good at this