Also wanted to add that a good amount of Electric Providers also do their tiered billing, meaning their cost per kilowatt isn't a fixed, flat-rate but there is a premium added to people who use a lot of electricity. Like people who are using <100% of what is the allotted KW in a household will get like a lower $/KW compared to someone who is using 120% of what their allotted KW for a household. If I remember correctly, someone who is using 200% of the allotted KW per household is paying roughly 3x per KW compared to someone who used <100%. Instead of the bill going 2x the cost, they actually have to pay 6x more for using twice the amount. Last time I've checked, there were 5 different tiers being used by my Electric Provider (PG&E) in my area.
So I guess picking an 80 gold efficient power supply has its merits so people can save as much energy to keep them away from the higher tier of billing.