Sam Walton hated .99 for some reason, so Walmart prices are never that.
It gives a feeling that they're slightly cheaper than the competition, I think. Even if the more significant digit is more expensive sometimes, people don't remember that part as much because it varies from day to day.
I'd wish Apple cut the crap on that, it makes them look like you're buying stuff from a used car lot.
You’ll never see decimals in a fancy restaurant for example.