I rescued a lab from a kill shelter down south. It cost me $400 and he was completely up to date with shots and neutered.
Food for a 70lb lab costs me about $30-40 a month using blue buffalo dry
Dog walker in boston costs $23/hr(!!!) although I only use it a few days a week when I can't make it home from work. I easily spend close to $200/mo on dog walking alone
Medical costs not including potential injuries run about 200-300/yr
There are also tons of intangible costs such as having to wake up an extra hour before work (5:45) in order to take him out for an hour walk/play time. Coming home during my lunch break to play with him almost every day. Not being able to go out after work for drinks or other activities because I need to go home and play with him.
Also not being able to just take off for a weekend unless I've made plans for his care like parents/friends/dog sitters
I know I'm forgetting more than a few things but don't just focus on the monetary cost of owning a dog..they are a HUGE responsibility