MsBerry, I'm trying to do what you are doing with delta for both outbound and inbound.
Do you know if you cancel it and immediately buy it again, you will get the same price?
If you cancel it and immediately buy again, you have to purchase the ticket at its current price. For Southwest, it's better not to cancel the flight but rather to reschedule the flight by choosing a different date or time. Actually, it doesn't even have to be a different flight. In the past, I saw that the price went down, so I clicked "reschedule" and bought the ticket at a lower price. I didn't get a refund, but the difference of the 2 tickets was credited to my account for future use. There is no 24 hour cancellation policy with Southwest. If you missed your flight or cancel it, the amount you paid for the ticket will be credited to your account for 1 year. I forgot whether it's 1 year from when you bought it or from when the flight is, but I think it's the latter.