Are small puppies usually healthy?

Hi,

I’m just wondering if anyone out there have small pups before? I really want to have a puppy (a small one, because I’m living in an apartment), but I’m just curious if small puppies are okay in terms of its health and stuff like that? and is it costly to take care of a small puppy?

Just for some additional info: the previous owner claimed that when it’s full grown it won’t be more than 5lbs. and it’s a pomeranian mixed with poodle.