How about links for both your claims?
"Unfortunately, however, determining the average electric bill in Phoenix during the summer is tricky given a lack of specific data. We can speak empirically, however, having been servicing air conditioners in Phoenix for more than 35 years. People living in 2,000 square foot homes (just slightly larger than the city’s average of about 1,600) typically spend within the ballpark of $450 per month during the peak summer months."
If you live in Phoenix, you probably know that summers here can be very expensive. Temperatures can climb as high as 105°, which will send even the most season
americanhomewater.com
"Monthly electric bills are a product of how much electricity you use per month and your electric rate. In Phoenix, AZ, the average monthly electric bill for residential customers is $181/month, which is calculated by multiplying the average monthly consumption by the average electric rate: 1,199 kWh * 15 ¢/kWh."
How much does electricity cost in Phoenix, AZ? Learn what average electric rates and electric bills looks like in Phoenix, AZ.
www.energysage.com
If folks paid $600/m for 6 months and the rest of the year was free, the monthly average would be $300.