First I would find out what you and your dad are allergic to... the dander or saliva (something in the saliva, but I can't remember the correct term). Yorkies don't shed, but if you are allergic to the dog saliva, then no dog will be allergy free for you both.
I then would consider how much time you will have to spend with your puppy- they are social animals ect.
I did not keep track of the vet expenses, and the dog food costs me more because I have a rotty on the same food (Innova) so I have no idea there either.
Good luck with your search
