When my dad purchased his canon selphy photo printer, he had so much fun editing and printing his pictures out the conventional way that I was sold once again on the conventional camera. So I decided to get a polaroid camera or Fuji Instax, now that polaroid no longer makes cameras. *sshh, I got him one too!
The instax minis are cute, coz the pics are about as big as a credit card. Or you can just use the "wide" film for conventional sized instant pics. For your inner child, there are rainbow and cartoon films at $16.50 per box of 10 films.
Approximate prices for the instax mini cameras are $150 for 7S, $190 for a mini 25 and $280 for a mini 50S. Of course, based on the colour choice and cartoon affiliation, it can cost more.