$400 - $500, depending on what you get. $400 would be the sweet spot. $450 I'd easily do. $500... MAYBE... if it were for like the super SKU that provided real value. But, $400 is a day 1 sale for me basically. $450 I'd spring. $500 I'd probably wait on it.
That generally holds true for a lot of consumer products for me, where if it hits $500 I say, "Do I really need this? Let's wait 6 months and see if I really need this."