That website is wrong. Price discrimination is perfectly legal unless it's done on the basis of a protected class (race, gender, etc.) or is deemed to be antico

That website is wrong. Price discrimination is perfectly legal unless it's done on the basis of a protected class (race, gender, etc.) or is deemed to be anticompetitive. But those are often the exception. Forms of price discrimination (bulk discounts, membership discounts, etc.) are exceedingly common and perfectly fine, as is price discrimination based on purchaser income or interest, its just often difficult to figure that out, but airlines and hotels commonly raise prices when you revisit their sites, under the assumption that you're more interested the second time around.