These Frozen Sparkle Princess dolls have been on sale for $10 at Walmart for a while, but out of stock. They are now showing available online but are out of stock in all of the stores I checked using major city postal codes. You might get lucky and find one in a store near you though.
If buying from Walmart, choose between Elsa or Anna (or buy them both). These dolls are available for free shipping to your local post office or free shipping to home if you spend over $50.
If you want free shipping to home, but do not want to spend $50, they are also available from Amazon.ca for the same price. Pick up Anna and Elsa for just $10 each. Add a $5 filler item to get free shipping if you do not have an Amazon Prime account.