I got Dovah from petsmart and they were feeding him fuzzie mice too, so that's what I bought... I ended up giving him all 3 that came in the package at once and immediately made the switch to adult mice... now he's on large adult mice and soon to be switched to rats.
Also, if you're buying your mice from petsmart or petco, it might be a good idea to go looking around for a breeder, or a mom and pop pet store, their prices will definitely be cheaper! Once you get to small rats it becomes like $10 a rat at big chain stores! I can buy xl rats for $4 at my local pet store.