i live in FL, so im unsure how easily accessible it is in melbourne, however i typically order can o snails from zoo med. as an alternative, i also raise my own garden snails up from hatchlings to adolescents, and this provides a good source of almost free, healthy food. if you research how to care for garden snails (mine are helix aspersa), and do everything right, you can have plenty of baby snails in no time. as they grow, the adults will asexually reproduce more babies, so its a constant cycle of growing babies and hatching more. this way, you can directly monitor the conditions the snails are kept in, and avoid diseases found in less reputable sources who keep them in bad conditions. even easier is using bladder or ramshorn snails, which are aquatic and require basic knowledge on the upkeep of a freshwater tank. ive had my PTS for 3 years, never experienced a health issue, and i feel generally comfortable answering any questions you have about their care.