The cost of dog in first 12 months will exceed cost of electrified poultry netting, fence charger, and other supplies. I would do both.Our budget isn't in the space for electric fencing. Our bee yard is already fenced off. The dogs have tried to get in there before and were unsuccessful.
My experience with starting pups with chickens is the pup make take out more chickens than the fox will if you do not invest in controlling the pup.