Basic supplies: Food bowls, a leash and toys can cost $35 to $50 even if you restrain yourself. Crates can cost an additional $50 to $150, depending on the size.
Food and water bowls can be picked up from the Dollar Store (they don't have to say DOG on them yo) or you can use something from your own cupboard. Washing bowls regularly is more important than paying for ones with fancy designs. A slip leash (the kind I prefer) can be purchased very inexpensively. Your Vet might even be willing to sell you one if they have adequate supply. Toys depend very much on the individual dog (you don't want the dog ingesting the toy) but a few ideas: empty plastic milk jugs (can be tied together), raw beef bones, knotted up socks or other old clothing bits, empty water bottles. If you need a crate, try checking your local paper or one of the many online resources (like freecycle or craigslist) where folks pass on used household items at no/low cost. Crates are easily cleaned so as long as the condition is good, there is no need to buy a new one.
• Food: What you can expect to pay to feed your new pet will depend on the size of your dog and the quality of the food. A 15-pound bag of dry food from a well-known national brand should cost about $17 at a grocery store, and will last two to four weeks, depending on the size of your dog (an average of $225 to $450 per year). Canned, or wet, food tends to be more expensive.
Healthy table scraps help me save on food costs because I share much of what I eat with the dogs and therefore, almost nothing goes to waste. For example, I may not finish the entire carton of eggs before the "sell by" date, but when I see it's getting close, I can hardboil the rest for the dogs.
• Health care: Expect to pay $200 to $300 a year for nonemergency vet bills, including an annual exam and preventive care for common problems such as heartworm, fleas and ticks.
Heartworm meds can be purchased at a far more reasonable cost than what the major brands go for, without a prescription, at your local feed store or online. HUGE savings right there.
Grooming: Professional grooming services are a necessity for certain breeds.
If interested, you can learn to do at least a passable dog haircut yourself from books at the library or by searching for "how to" pages online. I used to groom a Toy Poodle that showed up in our yard one day. He wouldn't have won any beauty contests with my grooming but it kept him from turning into the Shaggy Dog.
Alternately, if you don't have the desire to give regular haircuts at home (I feel ya), you can get a dog that doesn't need them.
Related Reading: Straight Talk on How You Can Keep Your Dog During the Economic Crisis