Can you return to ios6.1 after upgrading?

Currently using an iPhone 5 with iOS 6.1.3. If I upgrade to ios7, is there a way to go back to the previous version if I don't like it? Without jail breaking my phone of corse, and besides going to apple and ask them to do it, since they charge quite a lot of money to downgrade.

The upgrade is permanent. Once you upgrade, there's no going back.