We just got a sams card and found the formula prices were great too. I got the Sam?s brand formula with dha and ara (or whatever the brain nutrients are) 3lbs for 19.99. I also saw that I could get huge boxes of no name diapers for around 19.99 also.
It was something absurd like 158 size 5 diapers for 19.99! I have 2 kids in diapers so I use the cheaper ones during the day (I?m kinda picky on the cheap ones though they have to have stretchy bands on them and these do) and Huggies or Huggies overnights for nighttime because my dd who is 2 will wake up literally with a DRIPPING diaper if I don?t use a super absorbent diaper for nighttime.