Well ... if you were selling bikes to pay your bills, you would certainly want to sell a person as much bike as he or she would be willing to pay for.
It is not up to bike salespersons to help a person save cash ... their jobs are actually to help the customer Spend cash.
Anyone who ever worked on commission already knows. or anyone who worked in a shop with a low margin who realizes that the bigger the sale, the more likely the shop won't go under.
I think that as adults, we are supposed to have long since learned that all forms of advertising are designed to make people want to spend more and more money. If people fall for ads ... Hello, Darwin.