"I stash them everywhere for emergencies... I'm like a squirrel," said Jessica Stubbs.
Moms like Stubbs know diapers are a desperate, but costly, need.
"About 70 to 80 dollars a month. He goes through a lot of them... like about ten, eleven a day," said another mom.
For the first time, Washington Consumers Checkbook conducted a diaper price survey.
It shopped for diapers at local grocery stores, warehouse club stores, drugstores, discounters and online.
"We found depending on where you shop you can spend 500 to 900 dollars a year diapering just one kid," said Checkbook.org Executive Editor Kevin Brasler.
That's a difference of $400 per child each year.
Consumers Checkbook found some of the best prices on diapers at Target, Costco, Sam's Club, and BJs.
"You save a lot by buying in bulk," said Brasler.
It's no surprise Checkbook found the more diapers per package, the lower the per-unit price.
Buying a box of diapers with more than 120 diapers will likely save you 15-20%.
But this may be a surprise- Checkbook found rock bottom prices for brand name diapers online with Amazon. It's called Amazon Mom, part of its $79 annual prime membership.
Parents get two-day free shipping along with other perks.
"Prices there were far lower than any of the local stores we shopped... any of the online stores we shopped... you know 400-dollars in savings... a 79-fee doesn't look so bad," said Brasler.
Moms that use it love the price and diapers to their door.
You can save hundreds of dollars on diapers each year if you know where to buy.
"that's a pretty big deal for most parents," said Brasler.
And don't rule out generic brands. They are very cost efficient, but always try a small package before buying in bulk to make sure they work well for your child.