Walmart offers the 2 Munchkin Miracle 360 10-oz. Sippy Cups for $7.10. Opt for in-store pickup to dodge the $5.99 shipping fee and cut the price to $6.39. That's the lowest price we could find by $15, although we briefly (for less than an hour) saw them for $2 less three days ago. Each cup is BPA-free and has a 360° drinking edge that automatically seals after the child stops drinking.