A collectable will rise in value a lot more than a shooter... But as Steve and USMC said, if you enjoy them, it is better to have something than nothing! Just try to find the best that you can afford. I have come across a few deals while collecting, and also saved up and bought a few more expensive ones. Patience helps a lot!!
And USMC, ensure you get college and varied experience and then talk the civvie talk when you get out, us retirees do ok on the outside!
Ed