So, in order to keep our power consumption under about 2% of world wide power production, we cannot/do not want the price to get to $500,000 before era 6, which is about 2033 or so.
$500k in 2033? I'll take that. I can be patient. 
me too lol, imo 100k before 2020.
Bitcoin probably wont even be around by that time. Something similar but improved will have probably taken over.