I've had my common for two years now, and he was about the size of yours when I got him. He's currently in a 180 wide aquarium, and I'm planning on saving up for a 400 when I get a house.
They are great pets, but are not beginner at all. Definitely the most work, and most expenses of all my pets. Though I swear, I plan on having a snapper the rest of my days.
Right now, my biggest problem is with filtration. My filters crapped out, and I'm having problems getting them back up and running, so Dredge doesn't have much water to swin around in until I can afford new ones, or repair the current ones.
Anywho, back on topic. Sweet snapper! I do't care what anyone says, but baby snappers are the cutest. Ever. Then they get big, and are less cute, but more awesome.