Welp that's what my mom said at first too. I got some help my aunt to convince her. One of her friends was selling his old terrarium for 80€ together with all the decorations and items. And in addition to there happened to be a reptile trade fair nearby. Ironically my mom ended up loving them so much in the end, that she spent nearly more time watching them than I did.
Idk if it helps, but try telling your mom that these lizards can get rid of all the spiders and other nasty insects in your house.