I find the cost of a silver key is beyond unreasonable, to put it nicely. I would like to see them as a reward for completing a danger room, or some other source to reduce the cost. There could even be a time requirement or a survival element, if we need to be that stingy about getting a reward that usually offers no other benefit than a slight change in appearance. I understand there may be more conditions required to limit the amount of shadow keys available. I simply find fault with the current effort required to get something as useless as any accessory.
Some dilemmas with this idea include the inflated ratio of silver keys to lockboxes, the potentially harmful increased availability of shadow keys, and the inclusion of different possible required conditions for the reward.
I don't think the inflation would be too serious of a problem except the rate of receiving shadow keys from lockboxes might have to be adjusted if not eliminated. I personally don't attribute any value to accessories, in case I didn't make that clear already. If this is only my opinion, then I just don't know, maybe it's fine how it is.
-espil
Well, you're dealing with something that is designed to bring money in. I'm sure the playerbase wouldn't say no to keys that are cheaper and/or easier to get hold off, but with this I feel as long as there is a steady investment of energy being put into silver keys you're unlikely to see any long term change. Special promotions, maybe, but I can't see free silver keys becoming part of the long term goal.