My youngest daughter goes through sippy cups like candy. She is disabled and really bites down hard on the cups nipple. The cost can really add up when you have to continue purchasing new cups each week. I decided to head to Wal-mart and see if they had anything cheaper than what I was already buying.
I found a sippy cup by Nuby that promised to be spill-proof for the low price of $1.97. These cups are plain and do not come with any kind of design or special features. I didn't care though because I was looking for something that could save me money.
When I got home I added water to the cup and gave it to my daughter. (*tip: always try out new cups with water so you don't stain your child's clothing.) As soon as my daughter put her cup down on the couch I began to see the dark spot growing bigger and bigger. The cup was already leaking.
I wouldn't recommend this product unless you plan on keeping your children at the table and not letting them walk around with it.