Well, my fairly large pump runs, on average, eight hours daily and it's enough to keep the pool clean. I pay around 11 cents per kwh and that pump sucks up 2kw each hour or 22 cents hourly
So, at eight hours daily, that works out around 50 dollars a month give or take. Running 24/7 would work about to about $150/month.
I would just as soon keep my $100 bucks to spend on an adult beverage from time to time