Cargurus.com shows a couple in high 150s and quite a few in the 160-170k range. All relatively low miles and almost all are from authorized McLaren Dealers. I'd say that while not an absolute steal, if you get lucky you could snag one maybe at 150k flat.
If you are willing to consider 2016 with miles ~10-15k, you can get them as low as $147k (Note: There is one for 143k but it has a branded salvage title).
Enjoy life but be reasonable, you never know but you might actually live another day to pay for it!