So here is what happened, I think. Let this serve as a warning to others. Somehow, Tesla got it into their head/system that I had an Auto Pilot 2.0 computer. I was on a chat with Tesla and they told me that this is why it was $1800. They pointed to the page and said that it doesn't say hardware, it says computer: "This upgrade is available for $2,000 plus applicable tax, including installation, for vehicles equipped with Autopilot Computer 2.0 or 2.5 and for $1,500 plus applicable tax, including installation, for all other vehicles." They said that that my SC actually had a lower price than it should have been, that it should have been $2000.
However, my car was manufactured in April of 2014 which is before the AP 2.0 Computer was installed in cars. When I brought this to the attention of my SC, they told me the price was indeed $1500 and this pricing issue happened before and it was correct. So please be careful if you are told the MCU2 upgrade is anything other than what you expect. Get to the bottom of it and make check to see what AP Computer you actually have, because evidently that is the way they calculate the cost of the upgrade.