The term for that is "slap tagging."

When I ran the Marine Department at a major outdoor retailer, I was always fighting the warehouse team because they'd just roll out a high-end sonar unit in a cart for my people to stock and walk away, and there were people who would slap that them as shitty units from the same company, and the cashier wouldn't notice the difference between a Garmin 4CV (about $100) and a Garmin 8612 (about $5000).