I remember hearing of one study (I read this in Priceless by William Poundstone, good book), that compared the exact same product sold at $44, $39 and $34 through a split-tested mail order catalogue. Obviously, the $39 outsold the $44 as it was cheaper - but bizarrely, the $39 also outsold the $34.
There is a very weird power to the number 9 in pricing, I wouldn't underestimate it. If anyone wants further reading, I suggest googling "Charm Prices".