I don't know the science, but there must be some. The practice is commonly
referred to as 'psychological pricing'. We're a very small hotel gift shop
retailer . That style of pricing is so common, I think it's expected. And
our prices are high, so it might help ease the pain a little...

" wrote:

Mr. Knobb wrote:
I'm calculating retail prices at various gross profit
percentages. [...] I want the results to always round
up to the nearest 9, e.g. $3.29, 5.49, 2.99, etc.
How's this done?

And later:
I think I got it! Thanks!

I'm glad you found your solution. Now, could you please
explain why you -- and other retailers -- like prices
that end in 9, especially 9 cents as you asked for.

I'm just curious. It seems to be a pervasive trait.