Exorbitant price do give more profit per sales. For Illustration:
Super cake (only for example this item didn't really exist)
Base Price : 1,000
Selling at 25% @ 1,250
total sales = 4,
profit = 1000
Selling at 100% @ 2,000
total sales = 1
profit = 1000
While I haven't done more tasting on how long does it take to persuade customer at higher price, I still suggest using exorbitant price to maximize your profit. Serious Shopper helps a lot if you don't use the cheat-ish sure sale as it hasten the process to persuade them to buy. My bakery actually look pretty boring when i play for pure profit as I just sell baked alasaka over and over while slowly raising my baking skill.