Hello,
I have been thinking about this for awhile. Mainly because I came back to the game with the avatar feature already being unlocked. I remember it being the FIRST thing that I really wanted to get, because it individuated my account. In those days, your avatar did not get sent back to the vault after inactivity (otherwise I'd have a really cool avatar, I don't remember it, but it must have been really cool).
Something I realized while playing on my alt is that it is hard to get to the avatar option (unless he's been buying in the wrong category...). He has spent probably 11 cred