I currently have every single "limited time" mount/minion, so if I spent the time/money I could possibly be 100% complete. I guess this minion/mount would be the one that stops my collecting. I can definitely make it to top 100 for solo, but there's no way I can spend enough time to get to top 10, and there is even less chance I'll be able to find a pvp team that would want to spend the time in the group queue.

And even if someone was super good at PvP, it'll be hard to get top 10 in both solo and ranked. In Aether, no player was in both top 10s this round, so even the best players have a hard time doing so. Basically even if you are top 10 material, it's possible that one colour variant is out of your reach unless you take a vacation month from work or something.

I guess collecting was fun while it lasted, but time to call it quits. I usually stop caring/playing once completion becomes impossible.