I just saw a similarly optioned used '17 in Lightning Blue with just over 1600 miles at a Lexus dealer in NV. I am planning on putting in an order on an '18 or '19 in a few months, but figured I would see if I could get a deal that was worth buying that one right away.
By the time I finished my lunch at the place next door someone else was test driving it. I took look at it and was going to make an offer if the other guy didn't complete the sale. They just had "retail price" on the window, which appeared to be fairly consistent with MSRP for a loaded truck. I told the dealer there is a Ford dealer just up the street that sells their '18s at MSRP off the lot or on order (True), so there was no way anyone should pay in the 70's for a used '17. Long story short, the other guy bought it for $69,000.
There are a couple of MSRP dealers here, so the market is a little more buyer friendly than it is in Cali and you may be able to do a bit better, I would guess a little below MSRP.