Hubby and I adopted a dog last August. Expensive!!!! Of course, not as bad as having a child but still.
Take your estimated cost and at least double it. You will need heartworm prevention AND flea/tick prevention. The cost for both is around ~12 per month. That's a conservative estimate - assuming you catch the products on sale. If you adopt an adult dog you can probably skip the vet costs of all the distemper / lyme disease prevention / and misc. booster shots they must have as puppies. In the first six months, including spaying - we spent around $250 on our puppy at the vet alone. This was on top of her $300 adoption fee. When you adopt a puppy they aren't already neutered or spayed. That has to come after 6 months of age.
If you are adopting a puppy, I highly recommend you attend puppy classes and puppy "play time" at a local trusted and licensed training facility (no, not Petsmart!). Dogs need to learn bite control and the best way to do this when you adopt a puppy is to let them play with other puppies ALOT. The training classes will help with basic commands and will help to really solidify your bond with the puppy.
Depending upon the breed you will be dropping quite a bit on chew toys and bones. Ours is a lab / border collie mix and she loves to chew chew chew. If you don't want your shoes, socks, clothes, belts, electric cords, furniture, rugs, baseboards etc etc destroyed - you will need to keep a chewer busy.
🙂
Best most indestructable dog bones / toys I have found are made by West Paw. Available on amazon. Our dog has the treat glob, the bone, and the ball. Her favorite toys ever and she has tried to destroy them but cannot. She killed some kong toys, every rope and squeaker toy she's had, and even managed to destroy a couple of Nylabones.
http://www.amazon.com/West-Paw-Desig...1857600&sr=8-1
EDIT: PS, pick up a copy of the Dog Bible. Huge help when you are learning how to care for, and share a life with a dog. Best of luck to you!
http://www.amazon.com/Dog-Bible-Ever...1858080&sr=8-2