What do you want from the pet? Companionship, or guarding? Do you want a high energy dog? Any dog that is not exercised enough will chew up everything and have issues. More dominant breeds require you to be a strong owner, by that i mean confidence and the ability to set and maintain limits and boundaries. Decide what you want from the pet, how much you want to spend feeding and keeping it healthy at the vet.
Expenses to consider;
Food
Vacinations
Heartworm prevetative costs.
What kind of vacations you take, I.E. Boarding costs
Grooming costs if you get a dog that requires it.
Any fencing needs fixed or invisible fence.
Possible yard maintenace, dog pee kills grass, and if they are outside they wear a path in the yard. I have to seed and lime at least twice a year.
Other things to consider
Can you let it out every evening I.E. if you work way over, you may come home to dog piles.
Can you exercise the breed you select to keep them happy. A tired dog is a good dog! Your time every day, and yard size.
Do you have close neighbors, you don't want a dog that barks a lot and drives them nuts, and make them hate you.
Remember even in rain , bad weather, they still need to go out, and especially when young they still need exercise, or you will find your sofa chewed up!
think about the above things, and pick the size dog your home and yard can handle, then the temperament you want, then research health issues etc. I think some mixed breeds may have less health issues than pure breeds.
P.S. you need to keep money on hand for emergencies, injury, sickness or getting bitten by snakes, yellow jacket nests, or bitten by other dogs etc. I'd have $800 budgeted on hand for vet emergencies