old terrarium (Felixtowe)

Hi all, my boy wants to keep a pet snail. Sigh. He found one and brought it home, and it is currently in a tupperware box. It really needs a proper enclosure, but the kind of thing we need is crazy expensive, especially for a garden pest. Examples of ideal tanks are reptile enclosure, closed up fish tank, insect box, that kind of thing. We would really appreciate it