In case of McIntosh many people bought in order to sell again later for higher price - esp. with the Millennium MC2000 of which only 555 have been built. But as with many "collectibles" it turned out that nobody is willing to pay more than the former list price minus a decent discount. So since those people never intended to use the gear themselves they are in a hurry to sell it. Maybe they should wait another 10 years and prices would go up? Anyway, I was a HAPPY seller because of this and I only can encourage you do go for it. With a MAC you never can go wrong!
Best of luck
Best of luck