Two key factors are perception and competition.
Perception relates to the prices of predecessors at the time of launch of successors. The Xbox 360 launched at $400 at a time when PS2, Xbox and GC were all $150 or less already, so roughly three times as expensive; the PS3's launch price of $600 was 4-5 times as much the consoles from the previous gen. That looked a lot worse than during the transition from PS3 to PS4 and 360 to XB1 where the old consoles were $250 for a non-gimped SKU and the new consoles $400 and $500, respectively. So $500 won't look so bad for the PS5 and XB4 if their predecessors still have an MSRP of $250 by the time they launch.
However, the next question is competition. In a scenario where the PS5 launches at $400 and the XB4 at $500, or vice versa, $500 will look bad and the cheaper console will quickly gain the upper hand. One thing that wasn't present in 2013 is a strong Nintendo. It's much easier for people to hold out on new consoles when there is a viable alternative. Why rush to buy a $500 console with barely any new games when you can spend your time and money on a much cheaper console that has hit its stride; it won't be too hard to wait a year or two before taking the plunge. But the more important consideration in regards to competition is whether or not both the PS5 and XB4 will launch at the same price.