You can get the course at most university-based institutions. I do not know the cost. I takes you a full day (you will need also BLS).
As far as implications for residency application, not much, if any. I don't think it's well-spent money. Get what matters: scores, research, experience, LORs. If you can spend that money in books, that will improve your scores and make a substantial difference !
good luck
lf