Guild Wars 2

I don’t know whether or not this topic has been discussed in the forums yet since I couldn’t find anything related to it through the search function. Anyway, according to Guild wars 2 wiki, you should be able to buy anything you can buy with Karma with coins. So I have thought about the following discussion, would it be good to have a system for Karma exchange be it either through a) Fixed coins for Karma, b) pegged to Gem costs or some other item cost or c) free market transaction costs, like a trading post and what would be a good exchange system for karma would be. Or you like it as it is. I think it is okay as it is, but having this system in the future probably won’t be that bad imo.
What do you guys think?

personally i like the system we have, just would like to see more options to spend karma on.