You can only buy the mats for the "quota quest" which would take quite a long time at only 50 rep a day but the other quests you cannot buy the items for. The are untradable. At max rank you can but the new myth mats for 6 oaknots each which are only obtainable from the 2 highest tier quest givers. Also a new pair of i70 crafter hands which are arguably worse then the fully melded i55 crafter af hands. Other than that all your missing out on is the new minions and mount