Once the make all AH's connected, crystal prices should stabilize. However, I am all for keeping crystals at about 2-4k a stack because of the new players coming in. Selling crystals is an excellent way to make gil and is a much easier way to make it than the old method of beehive chips and grain seeds. New players get crystals automatically by leveling up solo from 1-20 and that's a lot of gil made to get them some decent armor.