I'd probably buy them in the order you listed with the camp last, since it only comes with a skin and not a character. But it's a tough choice between the first 2. I just think Barney makes Springfield more complete. Also when winter rolls around you can hope that his Plow King skin returns. Scorpio's 8 hour flame thrower task is cool, along with his 6 hour fun run task...his indoor tasks make his building open up, which is also sweet. So that might be a reason to go with him, especially if you enjoyed the episode.
