Five and dime

I took v to target and was going to teach the value of money by letting her spend her dimes on something in the dollar bin. But the dollar bin was half off..if there was a blue dot…and one color of glitter glue had the blue dot but the other had a black dot. We went to a price scanner and it turns out they were both 30 cents. I was going to have her go through the checkout and pay with her dimes but then I remembered tax. It is harder than I expected to teach the value of a dollar