There's no short answer for this question. Depends entirely on what you want.
You can pick up a shelter dog for a minor investment and hope for the best. I've done it and I lucked out: no health issues, dog lived a long and full life. To be perfectly honest that particular dog made me a better human being than I would have been otherwise, and that's no shyt.
If you have otherwise catholic tastes and any breed(s) of dog will do, well then you're in luck.
If, on the other hand, you want a dog capable of executing an extraordinary duty of some kind AND still being relatively free of health concerns AND all the while being a well tempered housemate AND beautiful to behold... well now, do your research and reach for your check book, brother.
I used to think pure bred dogs with all health clearances and pedigrees to brag about were obscenely expensive. Now I think they are one of the best bargains going. The initial cost of a very well bred dog is nothing compared to what you will put into it throughout its life and nothing compared to what it will give back to you.
