Board Thread:Game Discussion/@comment-5460671-20130520193113/@comment-9477730-20130520194044

It's extremely rare, my 1st random R4 card only came up from 2-3k of silver/gold metals ... that's 0.05%. The x3 episode raid cards seems slightly more likely, but it still go through 1k  cards or so to get one.

If you are using android, you can get mobicoins from installing other games from their invite ... then buy a raid card for 100 dollars.

If you don't do any of that, with 7k you should be able to get top 10k if you use your cube wisely on the last 2-3 days of the event. (Everyone get 60-70 cubes at the beginning of the event). This way you at least get 1 complete R4 card