Such a system would be cool, but must be implemented right. Here is what it needs:
1. Both parties can put material on the table, kinda similar to the trade system. That way, the crafter can supply some lower value materials or shards without the buyer going through the hassle of acquiring them (and possibly having to buy a big stack they don't need).
2. Buyer offers up two amounts of Gil: one for NQ and one for HQ. if the craft is successful, then the money and item automatically change hands for that amount.
3. Crafter offers up a collateral amount. If the craft is failed and materials are not recovered, then the buyer receives the collateral in compensation for the materials.
4. If the craft is failed and materials are recovered, they are returned to the player who put them on the table and no gil changes hands. Non-recoverable materials (shards) are lost. It would probably become common practice for the crafter to put up the shards.