That statement bears more truth than most!
If you're wanting to pep your suit then walmart would indeed be where to start. I would guess you need cardstock, hot glue (personal preference from experience with stick glue, elmers glue and super glue, hot glue has been the best to me) a gun for that hot glue (if you don't have one) and ink! If you're feeling like getting more than that and want to get supplied up I would also get some fiberglass cloth or mat (cloth is my preference) resin for your fiberglass and bondo.
If you're looking for the foam route you will still need hot glue but I'd hit up harbor freight (if you can find one near you) for the EVA foam, otherwise, you might have to find some on the interwebs, it's not always the easiest thing to come by. Plasti dip (to help coat the foam and give your paint job a better medium to sit on) is available at Lowes (and home depot I imagine).
you also might think about some sandpaper and possibly some gray primer, though if you got everything I mentioned already you've already got a punch to the wallet coming (though not bank breaker)
Good luck! If you feel overwhelmed you should try and get assigned to a mentee here:
http://www.405th.com/showthread.php/37153-405th-MENTOR-PROGRAM-3.0
Welcome to the 405th, good luck with your build!
Omega