This must be some kind of common sales technique then perhaps because I recently experienced this same playbook at a car dealership with the sales manager. After pulling out technical arguments as to why they couldn't do the price we agreed upon over email anymore, they went the emotional route and bluntly told me that I was hurting the well-being and livelihood of the sales person I was dealing with by not accepting their higher offer. I came in ready to purchase, but at that point, I exited as quickly as possible. This was supposedly a reputable dealership for a major car brand.