It will be pleasant if players could exchange stones achieved in Team Instances. An X number of purple stones will be equivalent to an y number of yellow ones. Only two close tiers could take part in (purple - yellow , yellow - red and never purple - red).

Restrictions : Only X number of low tier stones goes to one single higher stone. For example 3-5 purple stones turn into 1 yellow and 1-3 yellow stones turn to 1 red.