For now, I would suggest you collect income as often as possible. You get a surprising amount of gold keys per week just from multi-tributes, especially once you start 3 starring your kingdoms. This is the best source of free gold keys, by FAR. Once you start hitting legendary and mythic commons for the ones that have been around a while, you could also do what I do and hoard your gold keys for weeks at a time until the chests get some common drops, then open thousands to give you a head start on the new batch of commons and begin saving again. You may not have the newest common to mythic right away, but having them epic or legendary basically for free is a nice consolation prize.
Title is a bit ambiguous, but I’d support being able to open a few gold chests at a time with a single glory key. Having guild gold key tasks would probably be a more elegant solution, though, but if this is going to happen, it is not likely to happen until the next major version update. I would never spend straight glory on a gold key, unless they were priced so low that it would become a partial resource loop, which isn’t going to happen.