User blog comment:Akrie/My Experiences with Kakao Cookie Run/@comment-25889587-20150608160607/@comment-26044650-20150609151413

Grinding for Medals will take a very long time... and it's only if you're good and can place in the Top 12.

Being in the Top 12 only gives you 150 Medals. That's it. There are also 4 Episodes you can get Medals on (pretty much all Episodes sans Ghost Pirate's Island of Coins) so if you're REALLY good you can get 600 Medals.

However, the contest also lasts for a week (as well the Rankings). At best you'll get 2,400 Medals a month... only if you consisently place in the Top 12.

Frankly, for a normal player it's going to take a long time. :P

That is, assuming you're talking about the 3,200 Medals treasure. But for the other prizes, you can get it in a week to 2 weeks depending on the Medal costs.