Invoice price to a dealer may not necessarily be an indicator of the bottom price for a sale. Things like dealer volume of sales, advertizing allowances, special financing, monthly sales targets, etc may also factor into getting the lowest price. Good luck with her hunt.
Next thing you know he’ll want to see the dealer’s tax returns and income statments too........sheesh.....where does it stop?
Keep heading toward the door until they stop chasing you.
Then you know it is time to turn around.
The aftermarket is also a major consideration; dealerships make more money from their service department so they’ll give a break in order to have you come back for service. This is true of most big-ticket items- when I managed a camera store back in the 1980s we sold cameras at a loss because we got a 30% margin on film and 85% on photofinishing.