My suggestion is quite simple: Allow the Reward Tokens given by challenges to be converted.

I understand that the entire purpose of the Challenges was to encourage teamwork and fair play between individuals while working towards the goal of collecting enough tokens to purchase the new named items.
However, due to the fact that the free tokens available to all players are generated randomly, many free and premium players will not have access to the challenge(s) whose tokens they require. This creates an atmosphere of disinterest around the challenges for those that cannot take part.

My suggestion is simple, effective, and still requires individuals to actually experience the challenges. Allow me to explain my reasoning. There are four challenge areas with three challenges each that are non-epic. The individual challenges’ level ratings lend themselves to an “order” in which they can be attempted. If we sort the reward tokens by this logic, we get the following:

Tier I: Crude Talisman / Antique Coin / Obsidian Arrowhead / Enchanted Armor Fragment
Tier II: Necromantic Charm / Illuminated Manuscript / Jade Scorpion / Mephit Wing
Tier III: Orthon Metal Scrap / Jewelled Goblet / Crystallized Magma Shard / Arcanaloth Scroll

Allowing the conversion of tokens along these tiers would allow individuals much more flexibility in enjoying the challenges as a whole. The exchange rate should be 2:1 as this will discourage some individuals from simply replaying a single challenge ad nauseum in an attempt to grind tokens.

Epic Challenges are a different matter, and I will leave these alone as I am not familiar with Epic on DDO. If you have any ideas for the Epic Tokens, please feel free to add it, and I will try to update this post and give credit.