Multies are surprisingly expensive. Not sure why considering I started with about 12-15 and have well over 50 now (less than 6 months time). I paid $40 ( i think) for a 10g tank, hood, ac50, shells, sand, and the 12-15 multies), but that was a pretty good deal IMO. You can usually find them cheaper online on forums where people have just got too many and will ship them very cheap
As for auratus, its hit or miss. Juveniles are incredibly hard to vent, and females and males all look alike when they're young. Some people swear by egg spots, but I can tell you first hand that it's not a good method. I have a male and female auratus and they both have 5 egg spots. If you see one thats slightly lighter colored, thats a good indication that its a male (though there's no guarantee).
