[sheept]

Yes, as your parent comment points out, the article centers itself on US transactions, where listed prices seldom include tax and are frequently a cent below a round number. For example, the menu says a dish is $15.00 but the restaurant charges $18.83 after tax and tip. Globally, there's no doubt the US is the exception rather than the norm.

[panflute]

That sounds reasonable for some states but 5 states have no sales tax and many states have exclusions to sales tax. Many of those are also likely to have rural areas where small businesses like to use even amounts.