Trion really needs to fix this. There is no reason someone who puts so much time and effort into artifact collecting should only have 50 collections completed with 70 missing a single artifact, and many others missing only 2.
I rarely see anything I need on the auction house and I check it every few hours. I have foregone getting the normal epic mount because I have invested so much time into collecting artifacts to get the artifact mount.
Now I am only half way there and already level 50.
I hedged my bets by unlocking many collections and I check the AH thoroughly for artifacts I don't have. I make sure to buy anything for sets that are nearly complete. If I have left over gold, I buy artifacts for undiscovered sets, hoping that new collection will be easier to complete.
I have probably wasted a lot of gold on this. In hindsight I wish I had just saved up for the normal mount, but I've gone too far to turn back now.
I have picked up thousands of artifacts, and of those, only 3 have been rare. Only 1 of those was an artifact I didn't already have from the AH.
The entire system needs to be redone. IMO.
There should be two methods to completing a set. Collecting the single rare artifact or by collecting all of the common artifacts. That would net you the lucky coin either way. Collecting the rare and common artifacts would net a bonus.
Of course I expect detractors who are either extremely lucky or who are on higher pop. servers to not share my views. I still feel that Trion has needlessly made this aspect of the game tedious and unrewarding.