I can't comment on spay/neuter costs as my pups had it included in their adoption fees, however you will be looking at roughly the following expenses for a 60 to 70 lb dog (these are prices I have for my dogs ... depending on your location and vet, they may be higher or lower):
Food: ~$60-70 per month - this is for high quality food ... don't let the cost scare you ... cheap food, despite the poor nutritional value and all the other issues that go along with it, may seem inexpensive, but you will feed twice as much - end of month expense will be about the same
Vet: annual check-up ~$100 - 150
Toys and treats: $5 to 20/mos
Grooming: $180/year (this is for my small 20lb dog)
Emergency vet visits: $0 - $2500/year [depending on emergency, this can go much higher!!]
Then there are added costs as noted: blankets, crates, pillows, bowls, leash/collar, new couch/chair/carpet/door casing/baseboard moulding/and anything else the dog decided to chew and or destroy during the silly puppy years.