Every 2 or 3 months it changes for everyone when they +/- it by $500. It's not a negotiation. It is surprising to me they do this, I cannot understand the tweaking.
I was looking at a used car, and it changed price several times a week. You might also look at the experiences of used tesla buyers. The price isn't the only thing they've played with, they've been doing the same sorts of things with features and even warranty coverage, all of which have in general gotten worse.