I think my mom is a dumb shopper
Why do you think that about your mom?
I think she spends too much money. She always buys me things that are not needed.
Don't you think you should help her out then? You can take on some of the house hold responsibilities if you feel you could do a better job at them.
I don't want to help her shop.
Well if you are unhappy about what she gets you could make her a list. I think she might have an easier time if she knows exactly what you want from the store and not have to guess about it.