Extra fees later on is exploiting people who have invested time into the buying process and now have a higher price for saying no vs. whatever the extra fee is.

Extra fees later on is exploiting people who have invested time into the buying process and now have a higher price for saying no vs. whatever the extra fee is. It's rational consumer behavior, but it is not what you actually think it is. Vast majority of A/B testing schemes that do gotcha pricing cannot measure the 'credit rating' that your essentially burning by doing this, and it's only sustainable if they don't have any other choice of place that doesn't do this. It's classic short term PM metrics hacking in exchange for hurting the business or industry overall.