Air conditioning: Frequent on-off of outdoor unit or stay on for long duration
In a nut shell, the cooler your home, the more your electric bill will be. You pay for your unit to run, not to start up. Sure, there is an increase in current when the unit starts up but the increase only lasts for a few seconds and there is a slight voltage drop when this occurs. It will have a very negligible affect on you bill. Scenario 1 would be your best option.