i personally dont see the idea of getting a purebreed for $500 or whatever. i got my dog 11 years ago at north-shore animal league for a $50 donation (mix of black lab and hound, looks very much like a black lab).
she has a great disposition, was very obedient and easy to train (no need for a leash after 3 or so years), extremely friendly to strangers and good health.
purebreds have a tendency to be of worse health (think inbreeding) and the 3 purebreds i have seen the most (my sister's pitbull, aunt's yellow lab, and good friend's brown lab) were noticably harder to handle. not to say they werent friendly - but they had more behavioral issues.
i guess my main advice is to not rule out going to a pound, spending a few minutes w the different puppies, and picking one that approaches you in a friendly way. its def +EV [img]/images/graemlins/smile.gif[/img]
here's a pic for sh*ts and giggles:
