They're usually fairly easy to start from seed, but you need to start from fresh seed--less than a year old. Once the seedlings are up, they will stop growing at about the 6-leaf stage, and will need a treatment with crushed ice for 12 hours to start growth again. Only one cold treatment is needed in the plant's lifetime. For seedlings, check with really first rate cactus and succulent growers--look on the tags at your favorite garden center for buying cacti or succulents, and google the grower's name.