Crayons
Surprisingly, getting off-brand crayons and watercolor paints is a mistake. It is difficult to get any color out and you will need to buy the same products once more shortly after. You should buy something long-term instead at places like Target or Walmart.
Jewelry
Necklaces and rings for $1 may seem like a great deal but you should think realistically. What will the quality be like for a piece of jewelry that only costs $1? The material will likely change colors and the jewelry piece will break shortly afterward. Spending a little extra on some nice jewelry is definitely worth it.