Here's my problem - and this is the opinion of a "newer" player (11/20).  If you wanted the mission to be 3 x lvl 10 masteries it should be WAY later in the chain.  I can do every other quest around that quest (practically to the end of the chain) in hours to days.

1 lvl 10 mastery = 4,275 gold medals x 3 = 12,825 medals.

In GIV arena that's > 3,200 matches I have to win.

Assuming I win 75% of the time and matches take 75 seconds = that's ~90 hours ( of continuous Arena battles.  That's 2 and 1/4 full time work weeks.....

If you just do your 5 matches every day, then it will take you 2.34 YEARS to complete this quest.

This is really not fair to newer players as it used to be SO much easier to get badges and the mastery upgrade requirements were so much less.  All the Lvl 80+ people in my clan already had this one.

To put it in perspective, I won the Classic Arena Takedown in my group this weekend with > 2000 points and that was only good for upgrading 1 mastery from lvl 6 to lvl 7..... SO FAR from 3 x lvl 10.