The svn repo wasn't even a noticeable fraction of the traffic. It was files.wowace.com. The repacking of addons on every library update and the countless horde of mindless WAU users clicking update all addons everyday or even multiple times a day just to redownload all their addons that had a minor library update or a translation update for a locale they didn't even use was the major bandwidth problem.
And since WowAce was never ment to be an addon distrubtion website the goal of it was not to get as many people to use it as possible and 'make money'. It instead lost money, a lot of it.
Hopefully now that the repacking of addons on every library update doesn't happen anymore and that alpha versions are not the default for the updater, Curse will find out that the bandwidth usage has become reasonable and decide to let everybody keep the ability to update all addons in a single action. But on the other hand for the exact same reasons, you shouldn't have that many addons showing new versions every time you run the client so having to click once per addon with a new version isn't as bad as everybody is thinking it will be (everybody has a premium trial for now so nobody really knows right now).
There are very good bandwidth providers that charge you based upon sustained usage rather then GB or TB transferred. You can get colocation services at many ISPs for as low as $49/mbit per month. I'm not sure what you were being charged, but I would have paid $15/year to keep WAU. I hate the curse client. I hate the curse website. At least the wowace site was clean and I exclusively used ACE addons only.
www.curse.com <- that a way. This is not an addon distribution site.
You are an example of a person in that other group that doesn't really belong here. You only used WowAce because of the updater. You switched to only using Ace mods because of the updater. You think because its "Ace'd" its better probably. And you obviously have not participated in the community at all because if you had then you would know that we hate people calling it "ACE".
And let this be a warning to anybody else that used WowAce as a distribution site and comes here to complain. Prepare to be flamed.
Also all the available options to developers between WowAce and CurseForge are almost exactly the same. The only major difference is the community. But even though its allowed for now, using WowAce instead of CurseForge if you don't plan to really be part of the community really isn't very respectful to the community.