Depending on your use, I would also recommend buying the microphone. It is very useful for setup and you may want to run the auto-eq several times while you get your equipment and speakers setup. I've had my 3805 for 3-4 months and run the eq pretty frequently due to adjustments and speaker positioning.
That being said, your dealer might offer a "loaner" mic that you could borrow for setup. Many dealers are doing this because of the extra cost of the mic. It's not a big deal, but $65 is $65. Otherwise just buy it...it's worth owning.
Jason