You might find it useful to use a crate. If he sleeps in a crate you can take him directly from the crate outside to potty. He can then run loose. When you are not with him put him in the crate. Once he has the routine figured the he will become ...

I've only had my pup 5 weeks, but..
Vet 200
Toys 20
Crate 50
Bed 10 (she has outgrown it, need a new one)
food 20
total 300

This does not include what I paid for her....but she is worth it