I know what those are and it's silly to think anyone can predict what each customer's current (and randomly) generated pix level is each time they enter a shop.
And in the guide you linked to, you can see one very nice big notice right above those recommendations:
"The recommended prices listed below represent the current best guesses based on statistical data, experience and community consensus."
Also:
"The current version of the FAQ is based on the demo."
Which is very evident considering it doesn't even cover half of the remaining customer types (Alouette, Tielle, Caillou, Elan, Nagi, Griffe, Alma, Prime, etc.) or even 80% of the remaining game (only up to level 10).
I based my numbers off the translated Japanese wiki
here which has been around for years and my own personal experience after I beat the game and my current hellish and crazy experience on day 52 of survival mode.
Which one you want to believe is up to you.
Edit: Pricing in this game doesn't "really" matter so much as what you stock (6% difference is honestly NOTHING =|). So it's unlikely that in the normal casual game which pricing plan you choose makes a big difference. I still believe that anybody thinking pricing at such an oddly specific range yields higher probabilities of striking just price / near pix is just experiencing cluster bias or is a really strong proponent of selective amnesia.