> The fact that they went higher than I offered really just proves that I am low balling myself?
Yes.
Your boss knew how much it would cost them to find a replacement - short or long term - and your $65/hr came in below that. I am ecstatic that you are happy with that rate, but you probably could have earned more. Does it matter? Probably. But you're happy, they're happy, and I'm happy.
Next step? Get it all in writing. Sign a contract with them. If you haven't watched Mike Monteiro's excellent video on getting paid, take 40 minutes and watch it: http://vimeo.com/22053820
Enjoy your freedom, EOF!