That solution won't work. RMT bots will simply grind up to the required levels farming shards, once they have the level the bots will move on to crystals and the RMT will plant new bots for shards, and so on and so forth, all it will do is give the bots more gil as they sell the more expensive crystals/clusters, and make it more expensive on crafters, way more expensive (and as far as I can see, not a lot of crafters take into account the value of shards when they list the items for sale on the AH either).