if it takes a gopro to encourage you to go outside, buy neither and sit on your ass all doing nothing.
really, how frequently does it occur that you think "man it's nice out, I'd go outside, but I can't film everything I do in HD, then make a shitty edit to upload to youtube...so what's the point?"
but i'd buy the gopro, and try to pick up a used or refurbished xbox on the cheap.