I think I would reverse those two.
Strangely enough I wouldn't. And I do enjoy bubbly....
If you are superstitious (or cautious) enough to have a (re)naming ceremony, then going cheap in the "sacrifice" is guaranteed to risk the ire of good fortune, and many would say guarantee bad luck. Many people - for right or wrong - are concerned about renaming a boat to begin with; I reckon if you want to do it, do it right - don't shortchange Fate or the gods (or God) by cutting corners.
As a boat owner for a few years, let me assure you that a nicer bottle for the libation will be the least of your costs....
(another good renaming site: Renaming Your Boat - BoatSafe.com