I loved Nalgene Grip ‘n Gulp Sippy Cups for my kids when they were little! Right now you can get a set of 2 for $10.99! There are some really cute kids water bottles, too, as well as adult water bottles available.
Shipping starts at $5.95, and once you place an order, you’ll get free shipping the rest of the weekend on the entire site. There are lots of great deals on back to school clothes and shoes, so make sure you check out those sales.