I've been leveling all crafting classes fairly evenly .. and the shard rewards for Leves are nowhere near the production cost for the items being requested, for any of the classes, not once you get past the first few levels.

When you first started out, the crafting Guildmasters gave you some shards as part of the class quest rewards. They soon stop, and some time between then and when you start Triple Leves, you find that shard use skyrockets, to the point where Leves do not begin to cover their own shard use.