You are lucky - Beretta requires a copy of the receipt when registering a gun.
Honestly, for just a few bucks more, I'd wait and get a new one...
I paid $395 for my first one, and $449 for my 2nd one this past week. I am on a list, and could have gotten the 2nd one at the same shop for $395. But after 2 months of being "on the list," I got tired of waiting. I'm even #2 on that list