Earlier quoted context omitted.
> The sticker price should be the final price. God I wish this applied to buying cars as well
If you’re assertive enough, it is. “Oh, sorry, looks like we’d already applied the undercoat to your car.” “Ah, thanks!” “That’s an extra $400 charge.” “I’m not paying for it. I didn’t want it. You can have it back if you want.”
This is not as much of an upper hand as you think it is, often these shenanigans happen after sitting at the dealer for a couple hours while they do whatever it is they do. Do you value your time so little that you'll just walk out of a transaction over less than a 1% difference in cost?
The dealer knows how to play this game way better than you, if you walk into a dealership without having a plan to score a deal then you already lost