:I ru, i live at home. rent and job free. and my mother listens to my pet advice. heck, i prompted her to do her own research on the bearded dragon my sister's fiance bought, that we're going to lizard sit while she finishes her military duty in two years.
so, living at home, rent free is NOT the reason OP's parents won't listen to her.
if anything, it's because they're stubborn older people, stuck in their ways, convinced the pet store people are giving proper advice because they sell them.
which we know isn't true.
OP, why don't you try pullling up a care sheet or breeder's page, and calling your parents over. "hey, Mom. Dad. check this out. this website says they need this..." then pull up another. "Oh, this one says the same thing!"
that's what got Ma to talk sister's fiance into getting Spazz something other than the sand for his tank. so many websites said not to use it, so it must be bad, right? :V